Hi, I've just built the following circuit on the breadboard
http://circuitdiagram.org/automatic-nimh-battery-charger-circuit.html
I've got 9.3 v on the top rail, 3.9v on pin 2 of the 7805 and 7.9v on pin 3. The transistor on the right has 0.68v on its base and the one on the left has 0.11 on its base. The circuit gives the required output ie approx 180ma using approx 26 ohm resistance. However the led never lights even though the batteries are discharged. Is anyone able to shed any light on this? No pun intended! Thanks!
http://circuitdiagram.org/automatic-nimh-battery-charger-circuit.html
I've got 9.3 v on the top rail, 3.9v on pin 2 of the 7805 and 7.9v on pin 3. The transistor on the right has 0.68v on its base and the one on the left has 0.11 on its base. The circuit gives the required output ie approx 180ma using approx 26 ohm resistance. However the led never lights even though the batteries are discharged. Is anyone able to shed any light on this? No pun intended! Thanks!