Current loop 4-20 mA step 5 bits binary controlled (This example 0 to 31 mA)
Can be controlled with different kinds of logic command like Arduino, Raspberry Pi, Pico RP2040, ESP32, ... Or switches with pull-ups resistors for ex 3.3v 5v TTL CMOS...
For use: long distance current loop control, elaborate project. Resistor charge value can be milliOhms to 900 Ohms with constant current.
Interesting to have, Easy to build & cheap.
Instead 2 or 3 parallel E12 resistors could be used one E12 resistor & one trim (enough accurate).
Under 2.5 mA, it's BETTER to use diode instead PNP transistor.
Under 1 mA, it's better to touch around PNP transistor 10k resistor on base and 330R on emitter.
Be careful with PSU stability... Everything could be affected.
Brain storming and reflections are welcome !
With AmpOP, R2R, ... For example: command PSU like universal programmable PSU _ LED tester •••
•••Thanks•••
