Wiring circuitry

[dryan]

I've built a tank-like vehicle and need help setting up the control differently.

 

The drive-system of the vehicle is two independant motors, and each operate on 3 volts.

I need to be able to control each of the motors forward and backward.

 

Currently, I have a battery system where there are two seperate battery holders (2xAA each = 3v each).

One motor runs off one battery set, and one motor runs off the other.

 

The batteries are in the controller, and 4 wires go to the vehicle.

 

However, I'm wondering if there is a better way to do this. Most toy vehicles have one set of batteries to power all the motors.

 

The system I'm using works terrific, exept for consistant battery power. If I drive to the right more (use the left tread more), then that battery set runs out faster, and eventually I can no longer drive strait, but "vere" to one side, because one motor has slightly more power.

 

Do you guys have any ideas of how to make this work better?

[Cap'n Refsmmat]

Can you tell us more about the controller?

[dryan]

I'll do my best, because I'm not real sure if I understand all the way.

 

I have two 4-directional joysticks that I was given by a friend.

I only use the "up" and "down" of each joystick, to control forward and backward of each tread.

 

The joystick is on a circuit board. It has (I think...) a SPDT momentary switch for each direction. A tiny red button that the joystick depresses when you push it forward.

 

There are three connection points to the switch. One is "common" - always connected. The other two are toggled between each other. It is connected to the first one by default until you press the button and the connection switches to the other terminal.

 

I might have to draw out a wiring diagram for this, because it is kind of complicated how I managed to get it to work forward and backward.

I'm wireing both the forward and backward switch together, to make this work:

The (+) lead of the battery is connected to both of the "common"-terminals, I think... It was difficult to figure out a way to make it so it never shorts-out (you would have to press forward and backward at the same time, which is impossible with the joystick) and it would work both forward and backwards, but it is possible. I have proof, because the car works, except for the problems described above.

I'm sorry, I have to draw it out, and maybe look at what I did to explain the circuit I have any better. I'll draw this on Monday if I need to explain, as I won't be here this weekend.

[YT2095]

the problem is easily solved

you`ll need to make what we used to call a Diode CROM.

your one batery pack as the single supply will be just fine

then all you`ll need will be some Relays (the little 5 volt ones will be fine), you`ll only need the one joystick too.

 

wire the relays (you`ll need 2 per motor) so that when relay 1 is active the motor moves forwards, when relay 2 is active it moves backwards. do the same for the other motor.

then using simple diodes wired to your joystick switches, 1 connectection made will make one go backwards the other forwards, or the opposite to turn the other direction, both forwards or both backwards

no real ELECTRONICS involved, just basic electrics

[dryan]

I've though about doing it with one joystick, but I'm happy with the way it drives now with two - It gives a little more control. Driving with your design may work well for some applications, but I need to be able to adjust the direction while moving (stopping one of the motors momentarily while going forward). It also lets me pivot around one tread or the other, instead of the center which is nice in tight spaces. With your plan, it would mean a complete stop before turning.

 

I'll look into relays -- I'm new to building things like this, and so I don't know how or when to use diodes, resistors, relays, and so on. Using these would probably simplify things alot...my workarounds are pretty complex!

 

Work your brain on this one, because I made it work on a different motor, (though I've found better switches and don't have to do this any more):

Control a motor forward and backward:

1. Two momentary SPST buttons.

2. Batteries

3. Wire, tape, etc.

 

Can you figure it out?

No, because with only one set of batteries, you're either shorting the battery the whole time, or running the motor the whole time.

I setup two sets of batteries, one for forward, one for backward, and did a very complicated wireing system.

Wow, I wish I had a relay or a DPDT switch or something!

[YT2095]

use DCROMS! trust me! )

[dryan]

haha, I said I'd look for them.

Thanks for your help.

 

Can you point me to a site, or tell me what "DCROM" stands for?

Diode....

[dryan]

Do I need to make a voltage regulator? How do I keep a consistant voltage over two or three motors? Can I make a 3v output and a 6v output, all from a 7.2vLiION battery?

[YT2095]

haha' date=' I said I'd look for them.

Thanks for your help.

 

Can you point me to a site, or tell me what "DCROM" stands for?

Diode....[/quote']

diode, Changable, read only memory

 

we used to use them for preliminary boot sequences.

they ork in a grid system, a given signal on one the X axis will give an array output on the Y axis`s.

here`s some pics:

http://www.robotroom.com/AlphanumericDisplay.html

 

that`s just one possible aplication and you`de certainly not need a 256 array, as you can see it`s used to drive an LED display, but it could could just as easily control motors

 

a (very) breif description here at #41: http://66.102.9.104/search?q=cache:6qnh4u994csJ:faculty.ircc.edu/FACULTY/CPanayiotou/Logic%2520Circuits%2520II/Logic%2520Circuits%2520II%2520Study%2520Guide.doc+%22diode+ROM%22+electronics&hl=en

 

 

hope that helps a little