Railroader:
TIP120 is a Darlington transistor and unneccesary heavy transitor use for some 10 Amps. As I see a "normal" little NPN transistor would work.
thanks, is there any downside using unneccesary heavy transitor transitor (apart from higher cost)?
Railroader:
Why not let the Boost Converter run all the time and use a logic MOSFET N-channel switch the 36 volt? 2 resistors and one MOSFET.....
This was my initial version of the circuit, did work fine. But then I wanted to switch the boost converter due to power efficiency.
PerryBebbington:
You really should power the Nano from 5V not 12V, the on board regulator is crap. Use a buck converter.
What that downside when using Nano built in regulator? Will it eventually die?
I try to make everything as simple & small as possible. If I add another converter, I have two converters. With 12V input, then converting down to 3.3/5.0 for nano, and up to 32 V for solenoid. Wouldn't it be better in such a case to have supply of 32 V and use it for solenoid directly, and then only have one buck converter for the nano?
PerryBebbington:
I don't see any point to the double switching, just turn on and off the boost converter, unless you tried that and it caused a problem I cannot think of.
Good point. The circuit evolved, I first switched the solenoid, then wanted to switch boost converter too, that's the only reason.
I tried what you recommended but was not able to get it working. I was not able to switch the boost converter's 0V input with the nano. It was always on. I must be missing something obvious. Could you give me some hints on how the circuit would look like?
Thank for your help so far