Leon Borre DIY Transistor Diode Triac Tester

Transistors , Diodes, Triac's en Thyristors testbox.'

Thanks to Chris Woodruff for correcting this English text.

This simple testbox is made without any electronics, that way it is very easy to make, if you follow the schematic nothing can go wrong.

What we need :

A box size 7x5 cm. ( appox 2 3/4" x 2" ) Two double switches, two banana plugs ,a connecting wire, 4 resistors, ( values 10 , 2200 , 47 and 330 ohm) two LED's and three little hooks to grab the transistor or other component that is under test.

We must first drill some holes in the box so we can mount the switches and LED's.

Put the two switches on the sides and install the LED's in the top holes. In the bottom holes , install the three wires ( these will be attached to the hooks). On the underside of the box enters the wire bringing the 5 volts. A battery of 4,5 volts can be used to.

Everything is connected using this schematic.

Finishing;

We then put some labels on, identifying all the different elements.

The left the switch will be used to choose between NPN and PNP. The right the switch will be used to choose a small transistor ( norm) or a power transistor. The connections should be marked, E/Ka for the emitter or kathode; B/Ga to connect the base or gate, and C/An for the collector or anode.Both LED's are also marked PNP and NPN.

How to use.

TESTING DIODE'S

This basic schematic ( pictured below) shows how to test diodes. The left switch should be in the NPN position. The diode should be connected using the C/An and E/Ka hooks. If the NPN LED is "on" , then the anode of the diode is connected at C/An of the tester.

Now we change the left switch from NPN to PNP. If the LED stays "on" than the diode is bad( shorted) . If the led stays" off" in both cases the DIODE is bad , ( interrupted)

TESTING TRANSISTORS.

Here an example of a NPN transistor test. The left switch ( NPN/PNP ) is set to NPN ( of course , since it's a NPN transistor ) If the transistor is a power transistor set the right switch ( Normal/Power ) to " Power". The connection C/An goes to the collector of the transistor, the hook E/Ka to the emitter. The LED should stay " off". If the led is already " on " the transistor is bad, ( shorted) . Now we connect B/Ga to the base , the LED should go " on" if not then the transistor is bad.(burn out internal base connection).

TESTING OF THYRISTORS AND TRIAC'S

Set the left switch ( NPN/PNP) to the NPN position. The right switch ( Normal/Power ) should be in the " Power" position.The C/An hook should be connected to the anode of the thyristor , the E/Ka to the kathode. The LED should stay "off " Next we briefly touch the B/Ga hook to the gate of the thyristor, the LED should go " ON" and stay "ON".

Triacs are tested the same way as thyristors.

Professional tester.

Myself i use a professional tester ; this is an automatic analyser , it just has three little hooks how can connect at any unknow component any way you like. The tester finds what component it is and the characteristics of the component. These can be ; Transistors, ( included darlingtons and bipolars or diode protected C/E transistors) Thyristors , Triac's, Mosfets and junction FETs. Diodes, led's ( also two color led's). Scrolling down will read the HFE , VBE,VSS and at wich color hook ,base , collector and emmiter, is connected., Very handy.