I have hardware that wants a 10v PWM signal. My planned approach is similar to using a transistor to drive a 12v relay:
1) Supply +10V to the hardware
2) Connect the base of a transistor (through a resistor) to a PWM pin on the Arduino
3) Use the transistor to switch the GND connection form the hardware
Anyone see an issue with this?
Sounds OK, but be sure to wire a Arduino ground pin to the ground side of the external 10vdc source supply.
Thanks. I figured it was a sound approach but never having done it, and having no real background in this stuff, I wasn’t sure. Better to ask a stupid question than waste resources trying something that’s wrong!
The “external 10v supply” is likely to be a 10v voltage regulator on a shield that’ll also contain the transistors and a pin header for connecting to several of these devices, so the common ground is accounted for.
A relay's contacts have a limited number of cycles.
If you try to PWM a relay, the relay's lifetime will probably be measured in seconds.
Sorry for the confusion - I'm not actually feeding a signal to a relay - just mentioned that because it seems common practice to turn a relay with a control voltage other than 5v on/off with a GPIO pin as I've described. The device I'm feeding the signal to is made to receive a PWM signal, it just wants a 10v one instead of the Arduino's 5v.