Controlling 5 Volt solenoid with a 1 Volt signal

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Hello! I’m trying to control a 5V 1A solenoid with a knock sensor that produces 1V. I’ve been an auto tech for years so my first thought was finding a relay of some sort. The control side of the relay would again be controled by 1V and the switch side would need to be able to handle 5V at 1A. I’ve discovered solid state relays from digikey that seem like they’ll work but there is a lot of options and I want to make sure im not overlooking something. Also, is there an option for another component that could control this circuit? I had an electrical engineer suggest a Mosfet but I was struggling to find one that closes a circuit with just 1V. Do you have any suggestions?

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Welcome to the forum.

With a few pennies worth of parts, a basic bipolar transistor switching circuit can be built to switch an inexpensive 5V 1A relay with a zero to one volt control signal.

Details here:
https://www.electronics-tutorials.ws/transistor/tran_4.html

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Hello ScottK1,

This may be a good time to learn how to program a microcontroller.

Are you familiar with Arduino? This is an umbrella terms that refers to a line of microcontrollers but, perhaps more importantly, it refers to a large community of people who are dedicated to bringing programming and hardware design to hobbyists, high school students, and those beginning college.

With a microcontroller, you will be able to detect the signal likely using the transistor circuit @PaulHutch mentioned as an input buffer. You can then program the microcontroller to keep the relay active for a specified period of time. You may even add a few lights or a buzzer.

Note that the Arduino will not directly drive the relay. As you have suggested, you will need a solid-state relay, a MOSFET, or a Darlington transistor.

May I recommend an Arduino starter kit such as one these:

Each should contain a tutorial to help get you started. This may be a small book of experiments or links to online resources.

Best Wishes,

APDahlen

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