A very simple IR remote control tester schematic circuit that can be used for testing a IR remote control or IR device like IR barrier can bedesigned like in this circuit diagram , using few common electronic parts. The circuit use a TAA861 operational amplifier circuit used as an comparator and a photodiode BPW41, SFH205 or similar and other few external common components .
This Cable Tester circuit is simple and require few common components and can be used to verify in one time more conductors from cables . This device apply a different voltage to each conductor from the cable at one end . For indications this tester use light emitting diodes (led) which are powered from a constant current source given by a Lm317 voltage regulator .
The constant current is given by a simple formula I= 1,25/R2.
This circuit diagram project can be used for testing zener diode , we can measure the value of an unidentified Zener diode. This zener diode tester circuit it's centered around a common LM317 voltage regulator. The current is set to under 5mA, being calculated by the formula I = 1*25V/R, and this flows through the Zener diode being tested.
A voltmeter connected in parallel with the Zener its show the Zener voltage .