Op-Amp as a voltage switch

Hello,

My project involves actuating a couple of valves in a solenoid using logic signals, the only power access I have is a car battery (12V, ~40A)

I was wondering if it was possible to operate an op-amp as a voltage switch, here's the scenario:

  • arduino outputs 5v, low amperage
  • this signal is sent as a non-inverting input to an op-amp
  • the op-amp is sourced by a single-source high voltage, high amperage
  • the op-amp outputs a high voltage, high amperage signal

I was using these before:
http://www.ebay.co.uk/itm/20V-High-Side-Switch-module-Arduino-chipKIT-Launchpad-/190900133017?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item2c7288dc99

but i was an idiot and fried them all, and I need something to replicate that behavior that is easy to find locally, like an op-amp

I'd appreciate any help you can offer.

Thanks,

Ameen

I think a single discrete transistor - either MOSFET or BJT would work better here, they can supply more current than your typical opamp.

I need something to replicate that behavior that is easy to find locally,

so where are you? Fill in your location in your profile page.

Forget op amps they are a dead end. Use FETs like KeithRB suggested.

Opamps (unless very special) don't handle high currents.

Since you are going for solenoid valves, it is best to go for ULN series drivers. ULN2084 can drive upto 8 solenoids and can source a maximum of 500mA per solenoid. ULN drivers are low side driver. Discrete transistors would do, but if a driver IC is far more convenient if you have to drive multiple loads.

sreedevk:
Since you are going for solenoid valves, it is best to go for ULN series drivers. ULN2084 can drive upto 8 solenoids and can source a maximum of 500mA per solenoid. ULN drivers are low side driver. Discrete transistors would do, but if a driver IC is far more convenient if you have to drive multiple loads.

While this is true for each individual solonoides you can not have more than about 650mA going through that chip at any one time.