In this project, I'll make a small circuit capable of controlling a servo, it is a servo tester made out of a 555 timer IC.

Testing relays and their circuits in vehicles doesn’t always require a trip to the bench. With a few simple tools and knowledge, this video shows how to test relays directly in your car using a test ...

If you’re not short on cash, then the Chip Tester Pro may be more to your liking, however it’s hard to beat the simplicity and thriftiness of building your own simple tester from spare parts.