I removed the motors, and replaced them by the attached circuit. I replaced the motors with some 12V motors and This circuit is presently driving them. I can control them so both run at once or the left or right independently.
I am however trying to figure out a way to get by with using only one battery. I tried to tie them both together on one battery, but both of the motors would run and could not get them to run independently.
Is there a way to use a bridge or something to still power both by using the same battery?
I dont know what kind of receiver youre using… the transistors are NPN i see, maybe the base of them are floating? Try to add a pull down resistor (between - and the base) so you’re sure that the transistors are turned off when they get no signal.
Since I am not up on a lot of electronics, What size resistor would you suggest I try, and would I do that to both bases of each transistors? And so I get this straight, the resistor should go from the base to - (ground)?
Can you post a schematic of your setup with only one battery? It almost sounds like you are connecting your motors in series with each other.
I think you can use one battery, but you need to provide separate ground and power connections to each motor and transistor, so that those circuits don’t interfere with each other. Like this:
I wanna know sure is it’s something with the receiver (thats works maybe different then we all think) or if it’s something with the transistors…
try this: Disconnect the whole receiver, so only the 4 wires are left over. then connect one of the bases (WITH the 1K resistor between!!) to the + of the battery. what happens? are they still both turning?
That’s a good troubleshooting approach. Make sure when you disconnect the receiver that you leave the pulldown resistors in place so the disconnected wires don’t float high.
Using the schematic that shows both motors connected 1 battery, disconnecting the receiver, leaving the 10K resistors from the base to ground. I connected the + from the base through the 1K resistor, and only one motor ran.
Then connecting the + from the base through the other 1K resistor, the other motor ran. They both did not run in either case.
This is progress. It sounds like the transistors are working fine. It is something with your receiver itself, or with the wiring to your receiver.
Double-check your connections with a multimeter. See if there is a short between your receiver outputs while it is disconnected from the transistors. If you find no short, re-connect it and check for a short between the receiver outputs again.
Also try disconnecting your receiver and testing the outputs while you send commands from your transmitter. Verify that receiver output 2 is inactive when you are only commanding output 1 to turn on, and vice-versa.
Here are the readings I am getting from my meter with the 4 wires disconnected from the receiver to the circuit.
From the receiver there is a battery connection, and additionally two red wires, a yellow wire and a blue wire.
I connected the battery, thenI attached my meter from 1 red wire to the yellow wire, when I turned the left control stick on the transmitter (that would run both motors), the voltage would be around 5.16V. Then turning the right control stick on the transmitter (that would run one motor), in one direction, the voltage reading was 5.06V, then turning the right control stick on the transmitter the opposite direction, the voltage was 0.
Then I attached the same red wire to the blue wire, and followed exactly the same procedure. The left control stick (for both motors) was the same around 5.16V. However when turning the right control stick on the transmitter (that would run one motor), I got just the opposite results as I did before, as anticipated.
Then, using the other red wire, I followed the same procedure and got the same results.
Sorry, maybe I’m a bit slow this morning. I’m having trouble understanding your description.
Maybe a picture of your actual receiver and transmitter would help. Or model numbers so we can look them up.
My limited experience with RC receivers is that each channel has a three pin connection (power, ground, signal), typically used for running a servo. There’s sometimes a separate three pin connector that lets you connect power and ground input for the receiver, but I’ve also seen some where you use one of the servo connectors to provide power and ground for the receiver itself too.
Your drawing is very different from the above. It would help to understand what your equipment is.
I almost think the red wires are constant +, could you check this?
If so…it explains all: The motors then are controlled by switching the negative wire. This explains why they both run when connecting to 1 battery. In that case you should need PNP transistors instead of the NPN you’re using now with a slightly different circuit.
