I'd suggest a high-side switch. The HC-12 needs up to 200mA, depending on transmit power level, but can work OK down to 3.2 volts. So a small signal NPN (Eg BC548 or equivalent) driving a slightly stronger PNP (Try a BC327 or equivalent) should do the trick.Hi AllyCat,
Thank you for your remarks. I have checked the power consumtion 08M2 and get the following:
pause M16 1.14 mA
K250 0.27 mA
sleep M16 0.07 mA
K250 0.07 mA
So it seems that the job is to reduce the power consumption of HC-12 and the H-bridge/valve.
I am trying a transistor switch for that - without much luck so far.
I would use a 1k to 4.7k resistor for R1. Try 4.7k for R2 - this can be reduced as low as 1k if Q2 does not turn on sufficiently. R3 is just to ensure that Q2 turns off fully, so I'd use 10k.Hi inglewoodpete and AllyCat,
I am at the moment looking at activating a H-Bridge/valve and for that I need the high-side switch.
Can one say something about the values of R1, R2 and R3 when the load resistance is 5 kOhm? Actually one of the H-Bridges I might use shows OL for the resistance between the + and - terminals.
I think that I have cooked some transistors and would like to start with reasonable values.