duffman
Member
I am building a circuit and finished only to find a couple problems. I have an initial suspicion as to what the problem is however, if this doesnt work then ill lay it all out. I have soldered an lm7805. After powering up, applying the two ends of a 12 volt lamp, it lights up between the first pin and seoncd pin. duh. Its the pin that is getting external power, and the ground. However, i put the lamp between the second pin and the third and there is no light. This is strange because I am expecting a 5 volt output. However, there is none. Has anyone had a similar situation or know whats goign on? THe component seems fine, and the joints are all ok. I was under the impression that lm 7805s were cut and dry too. Just add voltage thats above 5 to pin 1, ground two, then three is 5 volts.