A small PCB module for efficiently driving a solenoid.
Rev B
Originally designed for use with drawing machines for fast up/down pen control but applicable to any project that involves driving a DC solenoid (as a guide > ~30 ohms). A TI DRV120 chip drives the solenoid with a configurable PWM frequency and takes care of the initial fast energize required to get the solenoid moving then ramps down the current to a lower level to hold the solenoid in place. Peak & keep (hold) current and PWM frequency are configurable with resistors and caps (see schematic and data sheet).
Testing with the chosen solenoid (MCSMO-0603S12STD) resulted in using a 4.7uF capacitor for C1 (KEEP), 47K ohm resistor for R1 (PEAK) and a 0 ohm resisitor for R2 (OSC) for the default PWM frequency value (~20kHz).
See datasheet for more details.
Rev B uses JST PH 2.00mm headers. If you are looking for a decent crimper that doesn't cost the earth, I can reccomend the IWISS SN-2549, available on Amazon for a lot less than the offical crimps. The litte extra jaws that jut out at the front do a decent job of crimping these small connectors.
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