and in fact that’s what [Dave]’s first LED tester was, in essence. Set an LM317 circuit up to output 10mA, say, and you can safely test out about any LED. Read off the operating voltage ...

The patented topology of FL7732 enables the most simplified circuit design ... level characteristics are well matched to board level test results. Fig. 3 Stored energy in output capacitance LED ...

It has an LED that illuminates — and it may also ... Turn the circuit off again as soon as you finish the test. Circuit ...

and in fact that’s what [Dave]’s first LED tester was, in essence. Set an LM317 circuit up to output 10mA, say, and you can safely test out about any LED. Read off the operating voltage ...