HI, <p>I am trying to use a controller from an RC car
to control a robot that I am building, and I need a way to use the outputs.<p>The way it's set up is:<p>there are four wires paired into two sets; one set for each joystick, so that when you press a joystick, there is 6VDC at 50ma max between two wires and when you press it the other way the polairity is reversed. I need a way to have the same outputs but up to two amps, I will have to use another battery but how do I do this. <p>
Any ideas?<p>Thanks John Paul.
Do you mean each joystick has four wires? Two for up/down, and two for left/right? Eight wires total?<p>Or, four wires total for two joysticks?<p>For each direction use two optocouplers with the LEDs in parallel but reverse polarity. Take up/down for example. In center neither LED is lit, so both opto-transistors are off (UPNOT = 1 and DOWNNOT = 1) no movement. Move the joystick up and the positive polarity LED lights turning on it's transistor (UPNOT = 0 and DOWNNOT = 1) forward movement. Visaversa when joystick is moved down. Now with separate logic signals you can control relays, H-bridges, etc to move the robot.<p>Repeat for the other dimension for turning. Repeat both for the other joystick for arm up/down, rotate, whatever.
It is four wires total two per joystick.
The way I was trying to do it is without a microcontroler, or any speed control, just simply 6v to the motors. I'm making it so that each stick controls one wheel, so that when you press it foward that wheel turns forward, and when you press it back the wheel turns back and same with the other wheel.
I just need more amps than the controler can provide.<p>I tried using a relay but I haven't been able to find any (execpt reed relays which can't handle the 2 amps) that are 50ma or less.
Have you tried power transistors? These will have very low current draw. Also they come in all different values so finding one capable of handling 2 amps should not be a problem.
-Jeff
John Paul,<p>I believe a pair of H-bridges would satisfy your needs just fine. Send an e-mail (look in my profile for address) if you'd like to hear more.
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