opamp tester

All types of operational amplifier can be functionally checked with the tes- ter proposed here. The principle of the tester is quite simple: a triangular voltage is applied to the inverting ( —) input of the specimen. This voltage is, of course, inverted. If then the inverted and the original triangular voltage are added, the result should be zero. Any devi- ations from this are taken as a mal- function which is indicated by one of two light-emitting diodes (LEDs). The tester has, of course, a self test facility so that the error-free operation of it can be readily ascertained. Opamps Al and A2 form a triangular pulse generator. Opamp Al operates as an integrator: capacitor C1is charged, and as soon as the voltage across it reaches the threshold value of Schmitt trigger A2, resistor 84 is connected to earth, and C1 the TL 084 used for A, ... A3), or in opamp tester discharges until the voltage across it reaches the second threshold of A2, when the process repeats itself. an 8-pi...