potentiometer cache

[mypaperpast]

this might be kind of hard to explain so i made a quick diagram that i will explain

 

 

now the idea is this...the potentiometers represented as O will be labeled 1-9...like a guitar volume knob minus the 10...and the x's would be green LED lights that will activate when a certain combonation of the pot positions is reached...for example...lets say the next numbers in the coordinats after the n 29 is 45....so in order for the green LED to light the two potentiomets below the x. would have to be positioned with the first pot at 4 and the second pot at 5...there will be a marking of some sort above the pot to allow the user to know what number to right down when he gets the right combo...you would use the same method to get the next set of numbers...and for the last number there is only one pot for one number....repeat for W coordinates....

 

now my question is this...how would i wire all this up and what components would i need...i know that linear potentiometers work on certain k ohms...take a 500k ohm pot for example...at it's half position it would only provide 250k ohms...so i'm thinking that whatever the position combo the total output for the two would have to equal whatever output is required to light the LED? is that correct...so would resistors have to be added?

 

i'm hoping i explained this idea enough for understanding and i hope someone can help with a schematic

[+dfx]

i can only tell you that you can't "combine" two pots by daisy-chaining them in the circuit (i.e. adding their resistances) for this purpose. because if e.g. the circuitry would require 500 ohms for the LED to light up, you'd be able to get that by having one pot be at 100 ohms and the second at 400, but also with 200 + 300 ohms, which would give the cacher different numbers.

 

how about not using real pots for this, but rather knobs that would silently toggle a builtin switch to ON at a certain position, and toggle it to OFF in any other position? that would save battery too.

Edited July 23, 2010 by dfx

[mypaperpast]

ahh..this is correct...so i'd have to use one pot for each number...but that really wouldn't be a challenge at all...you'd just have to turn each pot until the light comes on and no puzzle work at all

[+dfx]

ahh..this is correct...so i'd have to use one pot for each number...but that really wouldn't be a challenge at all...you'd just have to turn each pot until the light comes on and no puzzle work at all

no, you could still do it, just have to do it differently. the resistance of each pot would have to be considered independently, and then the good/bad result for two of the pots combined into one LED. no idea how you would do that electrically though. personally i'd just use logic gates, i.e. an AND gate, but that's because i'm an IT person. on the other hand, personally i wouldn't use pots at all, but rather plain on/off knobs, as explained above. also because i'm an IT person probably. and because it seems to be much simpler and more logical.

Edited July 23, 2010 by dfx

[mypaperpast]

yes...the on off toggle knob would be a good idea...and a much easier curcuit to wire...

[+TABjuggler]

On a similar note... is there any restriction on the type of math that is required to solve a puzzle cache?

 

I'd like to eventually make one using some pretty complex problems.

[mypaperpast]

On a similar note... is there any restriction on the type of math that is required to solve a puzzle cache?

 

I'd like to eventually make one using some pretty complex problems.

 

i don't think there are any restrictions on what kind of technique or even the difficulty of a puzzle cache...i've seen some puzzle cache pages that only have 20 pictures and you have to some how figure out what the coordinates are from those pictures...

[+jeffrae]

ahh..this is correct...so i'd have to use one pot for each number...but that really wouldn't be a challenge at all...you'd just have to turn each pot until the light comes on and no puzzle work at all

 

You could wire all the on/off switches in series and have just one LED for each set of coords. That would make it a pretty difficult puzzle though

Edited July 23, 2010 by jeffrae

[+TABjuggler]

On a similar note... is there any restriction on the type of math that is required to solve a puzzle cache?

 

I'd like to eventually make one using some pretty complex problems.

 

i don't think there are any restrictions on what kind of technique or even the difficulty of a puzzle cache...i've seen some puzzle cache pages that only have 20 pictures and you have to some how figure out what the coordinates are from those pictures...

 

Excellent.

 

The real question will be whether or not I only want finds from people with a degree in that field.

[+rjb43nh]

Pots would't be a good way to go because LEDs are current devices, not voltage. If a particular LED needs a minimum of 1.7 volts to produce light and has a current limiting resistor in series with it, any voltage above the minimum will cause the LED to light, with the higher voltage causing more current to flow through the resistor and LED, and thus producing more light until you reach a level of current flow that destroys the LED.

 

What you are trying to make is an analogue of a combination lock. The way to do that is to use a number of multi-position rotary switches wired in series so each switch represents one digit of the required number. Use a 1-pole 10 position for each digit you want. Go to THIS LINK ( http://info.ee.surrey.ac.uk/Teaching/Labs/...SwitchHowTo.pdf ) to see how it's done. You need to connect a wire to the switch common and another to the switch position representing the number for that digit. That wire will now be connected to the next switch's common with another wire to that switch's position representing the number for that digit and so on until you have the same number of switches as you need digits. The wire from the last switch goes through say a 1K ohm resistor to the LED and the entire string could work from a common 9 volt battery.

 

You could use just 5 rotary switches if you just need to find MM.MMM and not degrees, which probably won't be changing, or 8 rotary if you need DDD MM.MMM. You could use a toggle switch marked N/W and have 2 paths through the rotary switches to give you the numbers for both N and then W without doubling the number of rotary switches.

[mypaperpast]

wow..thanks...that's exactly what i'll need and probably will do....now all i need is a good schematic

[+DragonsWest]

Rotary switches are so unloved.

[+Jumpin' Jack Cache]

Call it Spinal Tap & turn 'em all up to eleven?

[+TABjuggler]

Call it Spinal Tap & turn 'em all up to eleven?

 

Agreed! That would be pretty neat.

[JohnX]

And the obvious question is: "How are you going to keep this thing powered?" The other observation is, if you are asking for schematics then perhaps you don't have the technical skills to bring your idea to fruition.

[+Capt. Bob]

And the obvious question is: "How are you going to keep this thing powered?" The other observation is, if you are asking for schematics then perhaps you don't have the technical skills to bring your idea to fruition.

 

For a power supply try this. On your front panel attach two empty “AA” battery holders in series. The cacher will have to use their GPS’s batteries, or spare ones if they have them, to power-up the system. A little backwoods MacGyvering on their part. This avoids dead winter batteries and users forgetting to turn the system off.

[+Stargazer22]

Go with switches, not pots.

Most volume control pots are not linear taper so simply setting one to the middle will not give you half of the total resistance. Most volume control pots are logarithmic taper and have a large amount of movement in the first portion of the adjustment as compared to the end of the adjustment.

Also, any pots of higher value resistance may be affected by humidity and can drift with age.

 

You could use some rotary switches and a simple logic chip so that only one combination of settings will light an LED. You could even go the fancy way and use a dual-colored LED that will be red until the right combination is reached, when it would go green.

 

You'll need to address the method of powering this device at the cache site, though. Be sure to alert cachers on the cache page if they need to bring batteries to power the switching unit. Don't assume all cachers use AA batteries, although most do. If they need to use AAs to power the unit you should let them know to bring some in advance.

 

Good luck on your cache!

[trotterlg]

IF I were to do this, I would use thumbwheel switches to select the number and use a normally open push button switch to hold down to activate the power to the system, should last for 10 years or more that way. Take a look at these switches, they appear to have 10 physical switch positions and not the 4 positions with a BCD type switch. Good luck. Larry

 

Switches

[mypaperpast]

And the obvious question is: "How are you going to keep this thing powered?" The other observation is, if you are asking for schematics then perhaps you don't have the technical skills to bring your idea to fruition.

 

well thank you johnx for your concern...the power issue is very easy...like everyone always says to do...make the cacher use the batteries out of thier gps or just bring and extra set...this is why i didn't ask about powering the system because that much i already have figured out...and for your second observation...i have plenty of knowledge in reading and soldering schematics...the reason i made this thread is to get the idea out that and get anyones possible advice on making it better or work more efficiently...also i have not purchased these parts yet for this project and would like to know for sure what i will want/need before i go spending money i don't have...

[mypaperpast]

Go with switches, not pots.

Most volume control pots are not linear taper so simply setting one to the middle will not give you half of the total resistance. Most volume control pots are logarithmic taper and have a large amount of movement in the first portion of the adjustment as compared to the end of the adjustment.

Also, any pots of higher value resistance may be affected by humidity and can drift with age.

 

You could use some rotary switches and a simple logic chip so that only one combination of settings will light an LED. You could even go the fancy way and use a dual-colored LED that will be red until the right combination is reached, when it would go green.

 

You'll need to address the method of powering this device at the cache site, though. Be sure to alert cachers on the cache page if they need to bring batteries to power the switching unit. Don't assume all cachers use AA batteries, although most do. If they need to use AAs to power the unit you should let them know to bring some in advance.

 

Good luck on your cache!

 

yes i do know there are audio taper and linear taper pots..i have changed out many pots for guitarist and for my own guitars...this is why i stated in the original idea that i was planning on use linear pots....and this is also why i've come to the conclusion that i will use rotary switches instead...but thank you anyways for the information you've provided...

[+Capt. Bob]

I threw together a quick schematic for a down and dirty layout. It uses a toggle switch to select North or West coordinates allowing the use of the same set of rotary switches for each coordinate just to keep the cost down. The rotary switches, of which I only show three (you can add as many as you can afford), are rotary, 2 pole, 10 terminal type. All you do is daisy-chain the switches according to your number coding. When the code has been dialed in correctly, the LED will light. Using this method requires the user to record the dial settings before toggling to the other pole.

These type of switches aren’t that common, but you can find them on e-bay fairly cheap. Look for Rotary switches 2p, 10t. If money is no object, you could double up on all of the components and eliminate the toggle switch.

 

[Difficult Run]

And the obvious question is: "How are you going to keep this thing powered?" The other observation is, if you are asking for schematics then perhaps you don't have the technical skills to bring your idea to fruition.

If you feel the need to phrase your comment in this fashion, then perhaps you don't have the social skills to express it politely.

 

I'm just saying ....

[+rjb43nh]

Capt. Bob's schematic is exactly what is needed. However, by adding two momentary switches, you can prevent battery drain when not in use and the second switch will verify that the batteries are good.

 

To check your numbers you set the rotary switches to the numbers you derived from the puzzle and push the switch to check to see if the LED lights to verify your answer. The battery test switch will eliminate the question of whether you have the right numbers but the LED doesn't light because the batteries are dead.

 

Added switches

[+Capt. Bob]

In my original drawing, I intended the batteries to be removed after use as I described in my earlier reply. The removal of the batteries would act as an ON/OFF switch. It’s about as simple as you can get.

[+TABjuggler]

I like the idea of the battery tester light too

 

I've never been a fan of something that has an on/off switch be the batteries itself.

[+mountainman38]

On a similar note... is there any restriction on the type of math that is required to solve a puzzle cache?

 

I'd like to eventually make one using some pretty complex problems.

No! No limits -- and please make a tough one.

 

Seems hard to find good, challenging math puzzles.

[+mountainman38]

....The other observation is, if you are asking for schematics then perhaps you don't have the technical skills to bring your idea to fruition.

Which is why he's asking for help here. Is there a requirement that someone must know all about a subject, before they attempt to do something with it?

 

How about some constructive input?

[+mountainman38]

Double tap.

Edited July 24, 2010 by mountainman38

[+Capt. Bob]

I like the idea of the battery tester light too

 

I've never been a fan of something that has an on/off switch be the batteries itself.

 

If you want to make the batteries non-removable (without being a switch function) then replace S1 with a 3 position switch. The switch should be configured as a MON-ON/OFF/MON-ON . With this design the system will always be OFF until the user manually holds the toggle switch in either the N or W position. Like I said before, the basic schematic is just that, bells and whistles are optional.

[mypaperpast]

I threw together a quick schematic for a down and dirty layout. It uses a toggle switch to select North or West coordinates allowing the use of the same set of rotary switches for each coordinate just to keep the cost down. The rotary switches, of which I only show three (you can add as many as you can afford), are rotary, 2 pole, 10 terminal type. All you do is daisy-chain the switches according to your number coding. When the code has been dialed in correctly, the LED will light. Using this method requires the user to record the dial settings before toggling to the other pole.

These type of switches aren’t that common, but you can find them on e-bay fairly cheap. Look for Rotary switches 2p, 10t. If money is no object, you could double up on all of the components and eliminate the toggle switch.

 

 

wow...thanks a lot capt. bob...this is exactly the help i was needing...someone with some knowledge on drawing schematics...i always know what kind of project i want to build but never realy know where to start...i'm going to order those parts pretty soon...and maybe use 4-5 rotary switches...

 

and for all the others with the comments for the "internet touch guy"...i still can't stop laughing...thanks a lot guys this is a lot of help!

[mypaperpast]

Capt. Bob's schematic is exactly what is needed. However, by adding two momentary switches, you can prevent battery drain when not in use and the second switch will verify that the batteries are good.

 

To check your numbers you set the rotary switches to the numbers you derived from the puzzle and push the switch to check to see if the LED lights to verify your answer. The battery test switch will eliminate the question of whether you have the right numbers but the LED doesn't light because the batteries are dead.

 

Added switches

 

your idea is also very great...but i believe i'm going to go with having the cacher use his/her own batteries...or i can wire a battery perminately like your schematic and also have a backup battery holder externally in case the batteries ever do run out....because as of right now...i do not cache with a gps and rarely have extra batteries on hand while i'm caching...and i know i'm not the only one...this will also all be pre noted on the cache page to bring extra batteries for backup just in case...thanks again for your guys' help...i'm going to start working on this in the upcoming week...i will post a link and pictures when it is complete....

[mypaperpast]

oh and one more question about the r1 resistor...so the math works this way? say i use a 9v battery...the equation would look like this (9-1.7)/.02 and that would give me the resistor value of 365...and that would be in ohms...so with the 365 ohm resistance what value of led would i need...

[mypaperpast]

haha..i feel like an idea...so my LED would be a 1.7v at 20milliamps? correct

[+Cardinal Red]

I threw together a quick schematic for a down and dirty layout. It uses a toggle switch to select North or West coordinates allowing the use of the same set of rotary switches for each coordinate just to keep the cost down. The rotary switches, of which I only show three (you can add as many as you can afford), are rotary, 2 pole, 10 terminal type. All you do is daisy-chain the switches according to your number coding. When the code has been dialed in correctly, the LED will light. Using this method requires the user to record the dial settings before toggling to the other pole.

These type of switches aren’t that common, but you can find them on e-bay fairly cheap. Look for Rotary switches 2p, 10t. If money is no object, you could double up on all of the components and eliminate the toggle switch.

 

Hey Bob

 

Don't you have the Battery Terminal polarities reversed? The Battery is inserted backwards if those polarities are corrected, right?

[mypaperpast]

I threw together a quick schematic for a down and dirty layout. It uses a toggle switch to select North or West coordinates allowing the use of the same set of rotary switches for each coordinate just to keep the cost down. The rotary switches, of which I only show three (you can add as many as you can afford), are rotary, 2 pole, 10 terminal type. All you do is daisy-chain the switches according to your number coding. When the code has been dialed in correctly, the LED will light. Using this method requires the user to record the dial settings before toggling to the other pole.

These type of switches aren’t that common, but you can find them on e-bay fairly cheap. Look for Rotary switches 2p, 10t. If money is no object, you could double up on all of the components and eliminate the toggle switch.

 

Hey Bob

 

Don't you have the Battery Terminal polarities reversed? The Battery is inserted backwards if those polarities are corrected, right?

 

i'm sure the curcuit would work both ways...but it probably is a better idea to wire the LED and resistor in sequence with the hot leads instead of the negatives...but either way...the curcuit would be complete no matter which way you wire....is this correct...

[+Cardinal Red]

i'm sure the curcuit would work both ways...but it probably is a better idea to wire the LED and resistor in sequence with the hot leads instead of the negatives...but either way...the curcuit would be complete no matter which way you wire....is this correct...

 

I'm sure the curcuit would NOT work both ways. LED1 is a Diode. Look it up.

[mypaperpast]

i'm sure the curcuit would work both ways...but it probably is a better idea to wire the LED and resistor in sequence with the hot leads instead of the negatives...but either way...the curcuit would be complete no matter which way you wire....is this correct...

 

I'm sure the curcuit would NOT work both ways. LED1 is a Diode. Look it up.

 

yes i know...light emiting diode....

[+Cardinal Red]

i'm sure the curcuit would work both ways...but it probably is a better idea to wire the LED and resistor in sequence with the hot leads instead of the negatives...but either way...the curcuit would be complete no matter which way you wire....is this correct...

 

I'm sure the curcuit would NOT work both ways. LED1 is a Diode. Look it up.

 

yes i know...light emiting diode....

Well, Emitting. But I'm still waiting to hear from Bob. Does he acknowledge there is a small issue with the schematic? And do you acknowledge you don't seem to know how a Diode works?

Edited July 24, 2010 by Cardinal Red

[savant9]

Well, Emitting, but I'm still waiting to hear from Bob. Does he acknowledge there a small issue with the schematic? And do you acknowledge you don't seem to know how a Diode works?

 

I don't know why I found that so funny but I laughed really hard when I read that.

 

It would seem that you are correct though, CR. As labelled the polarity is correct for the circuit, but the schematic image for "battery" is reversed.

[mypaperpast]

i'm sure the curcuit would work both ways...but it probably is a better idea to wire the LED and resistor in sequence with the hot leads instead of the negatives...but either way...the curcuit would be complete no matter which way you wire....is this correct...

 

I'm sure the curcuit would NOT work both ways. LED1 is a Diode. Look it up.

 

yes i know...light emiting diode....

Well, Emitting. But I'm still waiting to hear from Bob. Does he acknowledge there is a small issue with the schematic? And do you acknowledge you don't seem to know how a Diode works?

 

i am achnowledging that i do know how a diode works...previously i was simply stating that whichever direction the + - were..you'd simply wire the diode accordingly

[+rjb43nh]

Cardinal Red-"...Does he acknowledge there is a small issue with the schematic? And do you acknowledge you don't seem to know how a Diode works?"

I’m sure that with your vast knowledge you could offer many more constructive comments. The battery being schematically drawn backwards I sure was a slip, no different than the misspelled words we all let slip now and then. Before anyone picks further and says the rotary switches are also drawn incorrectly, I’m sure they were drawn the way they were to allow people to follow the logical path for both N & W. Physically both sections of a rotary switch will be on the same position terminal and not on different ones as shown in the schematic. I saw nothing wrong with showing the two sections in different positions to illustrate a point.

 

But just to make it clearer for some, here is yet another version of the schematic with the battery test switch, which I feel is necessary, included. I eliminated the push to read switch I had added and went with Capt. Bob’s suggestion of a momentary 1P2T center off switch to accomplish both N-W check functions and power off in one switch, a better idea.

 

[mypaperpast]

very nice...this is what i had in mind for a visual layout...

 

[+Cardinal Red]

Before anyone says the rotary switches are drawn incorrectly, I’m sure they were drawn the way they were to allow people to follow the logical path for both N & W. Physically both sections of a rotary switch will be on the same position terminal and not on different ones as shown in the schematic. I saw nothing wrong with showing the two sections in different positions to illustrate a point. (slight edit by me - CR)

I don't see anything wrong with it either, because the dashed lines linking the poles indicate one physical switch with two poles ganged to one shaft. In the absence of those dashed lines or something like S1A / S1B labels they would indeed be physically separate and individually selectable. Schematic reading 101. And individual (not ganged) switches could increase the difficulty of arriving at the correct solution for N and W which could be wired to require solving them simultaneously, not individually.

 

Note: After the positive effect of some sleep time, I have taken advantage of my 24 hour edit window to more precisely word my message.

Edited July 25, 2010 by Cardinal Red

[mypaperpast]

i've even come up with a theme for this cache...the cache title will be "you have one phone call"....and an old corded phone will be attached to the side of the box and wired to act as a universal on/off switch (mainly for looks for the cache)...because the hints for the differnt combo's will be area codes from different city...example...hint for N coords will be "houston, tx area code".....this way the cacher isn't sitting there for hours going through all the possible combonations...and just so happens that the coords N 29° 45.281 W 094° 57.713...lands right outside the baytown, tx jail house...281 and 713 are both houston, tx area codes...how ironic

[trotterlg]

very nice...this is what i had in mind for a visual layout...

 

 

rjb43nh

 

Your battery polerity is incorrect, the minus side is the one with the long part and the positive has the short side. The previous schematics are correct. Larry

[+Cardinal Red]

rjb43nh

 

Your battery polerity is incorrect, the minus side is the one with the long part and the positive has the short side. The previous schematics are correct. Larry

Hi Larry. I disagree with your view of Battery polarity. Would you care to link to an example of a circuit on the web labeled as you describe? Please feel free to use an electron flow, conventional flow or hole flow example if you think it will help.

[JohnX]

....The other observation is, if you are asking for schematics then perhaps you don't have the technical skills to bring your idea to fruition.

Which is why he's asking for help here. Is there a requirement that someone must know all about a subject, before they attempt to do something with it?

 

How about some constructive input?

I believe my input was constructive. Warning someone they might not be able to achieve their goals and will possibly be wasting their time and money is not wrong. As far as constructive input,asking questions on how you are going to solve a problem is a typical Engineering design review process. I guess it's bad to be an Engineer, which you clearly are not. A question to ask is how can you waterproof this thing? I have no idea how you can do it. It is not a simple project.

[+rjb43nh]

trotterlg-"rjb43nh

 

Your battery polerity is incorrect, the minus side is the one with the long part and the positive has the short side. The previous schematics are correct. Larry"

Cardinal Red and I are right on the schematic symbol for battery polarity. Do a Google search for "battery symbol" and you will find the following, as shown in this screen capture.

 

[+mountainman38]

....The other observation is, if you are asking for schematics then perhaps you don't have the technical skills to bring your idea to fruition.

Which is why he's asking for help here. Is there a requirement that someone must know all about a subject, before they attempt to do something with it?

 

How about some constructive input?

I believe my input was constructive. Warning someone they might not be able to achieve their goals and will possibly be wasting their time and money is not wrong. As far as constructive input,asking questions on how you are going to solve a problem is a typical Engineering design review process. I guess it's bad to be an Engineer, which you clearly are not. A question to ask is how can you waterproof this thing? I have no idea how you can do it. It is not a simple project.

 

Wow -- you just keep getting better and better. You're right -- warning someone about the complexity of a project and that they may have a difficult time IS a good idea -- but this is not what you did. It appears that your style is to mock the question asker, instead of offering useful input, then try to backpedal later.

 

Where did you pull the "you are clearly not an engineer" comment from?! Whether I am or not has no bearing whatever on the point under discussion. To further point up your own limited observational abilities, I am in fact an engineer. Are you? And what difference does it make?

[JohnX]

....The other observation is, if you are asking for schematics then perhaps you don't have the technical skills to bring your idea to fruition.

Which is why he's asking for help here. Is there a requirement that someone must know all about a subject, before they attempt to do something with it?

 

How about some constructive input?

I believe my input was constructive. Warning someone they might not be able to achieve their goals and will possibly be wasting their time and money is not wrong. As far as constructive input,asking questions on how you are going to solve a problem is a typical Engineering design review process. I guess it's bad to be an Engineer, which you clearly are not. A question to ask is how can you waterproof this thing? I have no idea how you can do it. It is not a simple project.

 

Wow -- you just keep getting better and better. You're right -- warning someone about the complexity of a project and that they may have a difficult time IS a good idea -- but this is not what you did. It appears that your style is to mock the question asker, instead of offering useful input, then try to backpedal later.

 

Where did you pull the "you are clearly not an engineer" comment from?! Whether I am or not has no bearing whatever on the point under discussion. To further point up your own limited observational abilities, I am in fact an engineer. Are you? And what difference does it make?

No back pedaling here, you commented on constrictive input and I think I asked a reasonable question. Thank you for your input on my terse comments, I sometimes get testy. I will tone it down in the future. To answer your questions, from your comments and my experience I believed you were not an Engineer. To answer your question if I am an Engineer, I have two Engineering degrees and a degree in a foreign language. Thank you for asking because my answer allows me to look like an arrogant braggart.