Hi there ,
here ist my really first start project in electronics . I bought a C30 oscilloscope made by Grundig from Ebay and there is no component tester inside this unit . So I decided to build one by myself . The cost of the ordered parts were less than 30 € and the schematic is really really easy . You can see on the pics that it is all built in in one housing , the C13 socket with 2 pole switch and fuse for the source , the transformer 230V/9V 155mA , the 20k resistor , the control light , the bnc sockets to connect to the oscilloscope and the banana jacks to connect the test object .
Primany circuit and secondary circuit are installed seperately and all contacts of the primany circuit are shrunked for safety reasons . It made lots of fun to build it and I checked it out and it works well .
For myself it was a little trip in the past . When I learnt my job electrician in the firm they also repaired audio stuff like radios and TV s and the guy who did the job shew me how to look for defective diodes and transistors with an oscilloscope . I remember it was a hameg 400 series with built in component tester . He was an electronic student and a really clever guy .
Here are some pics of my homemade component tester and the schematic for that