Hi, this is Wayne again with a topic “Weekend Projects – Battery Clip Transistor Tester”.
Hi, i’m adam with make. Are you the type of maker who likes to experiment with npn transistors, whether you prototype your circuits on breadboard or build them on perf board chances? Are you have a drunk drawer that collects potentially inoperable components with most two-lead components like leds, resistors and capacitors? It’S easy to test them by supplying voltage to one lead and ground to another or by using your preferred multimeter. But three lead transistors can be a little tricky to test, even with plunger mini hooks attached to your multimeter in today’s weekend project by nick normal, you can leave your multimeter in the drawer as you assemble this tiny battery clip transistor tester. That will quickly, let you know if your npn transistors are operating correctly.
You only need a handful of components to build this circuit. If you don’t have the parts as leftovers from other projects, you can pick them up at your local radio. Shack you’ll also need these tools. Okay, so first a little about bipolar junction, transistors transistors come in many types and packages, but the most common types are. These three lead npn transistors identified as package type to92 you’ll notice. One side is curved and the other is flat. Usually the flat side has some information imprinted on it. There are over a hundred package types still commonly manufactured, but this kind is most frequently found in maker projects always check your component’s data sheet, but this is the most common arrangement of pins on the npn transistor. In a transistor, the base blocks electricity from flowing from the collector to the emitter.
When the base is activated, electricity can freely flow from the collector to the emitter. In this sense, the base is a lot like a momentary switch. This is important when it comes to identifying which connections are made when soldering the circuit. This circuit is super simple. Without the collector base junction connection, the circuit is inert as soon as the collector-based junction is established, with the use of a fingertip switch. In this case, the red led will light up, and electricity will adequately flow from voltage to ground.
That’S all that’s going on here and rather than using the transistor in a circuit, we’re going to use this design to make a tool to test transistors. First cut two pieces of perf board down to size, use a rotary tool and a cut off wheel and be patient, as these cuts are quite small and precise. One piece will accommodate the bulk of the components and the tiny pad will act as a momentary switch when pressed with a finger, use any three pin header or make a three pin header from single pin headers.
You might already have something similar in your workshop’s junk drawer, cut and strip the wires insert the resistor led and three pin header in the large perf board per the circuit diagram. You can find the circuit schematic and diagram over on the project page bend. The component leads, so you can flip over the perf board and solder the components in place now cut and strip. The three short lengths of wire two will be soldered to jump. The transistor’s, collector and base points to the tiny fingertip switch pad the other length of wire will jump the transistor’s emitter to ground solder, these in place per the diagram cut and strip the battery snap connector’s leads to a short length and solder. These leads to the perf board.
Lastly, apply: a small dab of hot glue to the top of a battery snap, connector and press the perf board firmly into the glue hold this in place for a minute. You now have a super simple homemade tool for testing npn transistors. Let’S try it out insert any common npn transistor in the three pin header align, the transistor leads, so they correspond with the circuit’s collector base. Emitter points, press, the tiny pad on the front and the red led should light up. This means your transistor’s collector-based junction is operating properly and you can use the transistor in any circuit. You want to build now. It should be noted that this tool only works with testing npn transistors, not pnp transistors. This is because their pinouts are different and the circuit to power the led would be different check out the project page for more details or challenge yourself to figure out how you would redesign this circuit to operate with pnps share your build with us or any other Projects you build with your favorite transistor types. You .