Hey guys, I've taken apart a cheap r/c car so that I can use it to control some much more powerful motors instead of the dinky ones that come with it. Since there are basically two channels, each of them has 2 leads and the polarity is switched on the leads to change the direction of the motors, but if I want to power stronger motors, I'm assuming I need to use some transistors and/or diodes for this, I could probably use logic gates w/ transistors also, but is there a way with just transistors and/or diodes? CH1: 0 0 (+/-) or (-/+) CH2: 0 0 (+/-) or (-/+)
yes, you can beef it up with a FET/ Power darlington h-brige. I'll come up with some schematics for you. What kind of power are we talking about though? are you just trying to run something slightly bigger, or something a lot bigger? In FIRST robotics, our drive motors, can draw up to 114 amps at stall, and they aren't that big at all. (and we have 4 of them, so stalling them is a big no-no ) I have a feeling you don't need that much power. But how much stally curent are we talking about with your motor? If you don't have the datasheet handy, just measure the resistance of the motor with a multimeter, and use I=V/R to determing the current (I). That is usualy pretty close to the stall current. I'll work on the schematic for ya and post it later. Oh believe it or not, the tiny little motors in power wheels kids toys, can draw almost 150 amps when stalled. They pack a ton of power, but can overheat qucikly, but they are relatively small, so don't let the size of a motor fool you. EDIT: That would be the basic setup. might need something else though (besides base resistors...), especially if your new power source is of a higher voltage than your old one. I'm not so hot when it comes to transistors right now. I'm more into the digital stuff, but different kinds of motors are starting to interest me now.
I'm assuming what other thing that might be needed is a diode across the load, so that it will normally not conduct, right? Also, any idea how to calculate what value the base resistor should be?
