If you give us some more info on what the voltages and currents you need are, plus whatever PNPs you can find, then I can sketch you up a circuit diagram.ĮDIT: You could also use the ULN2803 to control the speed of the motor, and use a DPDT relay to select the direction. You don’t really need protection diodes (normally a definite must) since the UNL2803 already has two per output, which can be used to protect the circuit provided you wire it up correctly. Depending on what class of ULN2803 (A, B, etc) you usually won’t need an input resistor, but you’ll need a resistor for each of the PNPs.Īlthough that’s the minimum configuration it’s also nice to add a few filter capacitors to smooth things out.
You can use two of the ULN2803’s channels + two 500mA+ PNPs for a 500mA max current H-Bridges, or you can stack up to 4 ULN2803 channel together and use two 2A+ PNPs for a max current drive of up to 2A. I suggest finding some PNP transistors with 500mA or higher emitter-collector current. You’ll need, at minimum, two PNP transistors and two resistors in addition to the ULN2803 to complete the circuit. I’ve built several H-Bridges using the ULN2803A, it’s an extremely convenient IC.
0 kommentar(er)
