Best way to drive a 10 Amp Solenoid??? Please help!!!

[dvstate]

I'm working on designing a PWM solenoid controller using a 12F675. I have most of the software developed and tested using LEDs, but now I need to find a way to drive the solenoids which require 10 Amps!

I have 12VDC. What is the best, cheapest, and most reliable way to drive the solenoids? Relay? Mosfet? Other?

Thanks!

[j11]

depends on how fast the response needs to be. If speed is important use a mosfet with the associated charge pump on the gate circuit. IR (International Rectifier) has the parts and the app. notes to do this. Relays will work but they have an appreciable delay from being commanded to a specific state and actually reaching that state.

cheers

[John P]

10 amps is one big honkin' solenoid. It must make quite a bang!

I'd say MOSFET is the easiest drive (don't forget a freewheeling diode). You might be able to use a "logic level MOSFET" with a gate which would run directly from a processor pin--don't know if they're available in that current range.

That solenoid of yours will sit there burning 120 watts while it's energized. For extra credit, you could install a setup which would zap it with a 100% duty cycle for (let's say) 1 second when it first turns on, and then pulse-width-modulate the drive to save power and reduce heating. Remember that a solenoid produces much more force when the plunger is all the way in, so after a brief interval you don't usually need full power. But if you do this, consider the characteristics of the freewheeling diode. Don't use a regular diode with a fast PWM drive; use a fast-recovery type.

[Amsterdamned]

Usa a TOPFET and you dont need a extra component but it is saver to use the freeweeling rectifier!

Greetings,
Amsterdamned.

[Yashu]

Watch out for glitching occuring on your ground when turn the thing on/off. You probably don't want to turn that FET on 'hard'.