I made a project where two 6V relay is supplied from a 9v regulated dc supply. this dc supply is made up with 12V transformer, bridge rectifier, 100uF filtering cap, LM 7809 and a 10nF cap.
when no relays are energized output voltage is nearly 9v. when one relay is energized voltage drops to nearly 7v. and when both relays are energised voltage drops to nearly 5v. each relay is driven by bc547 transistor with 1k base resistor. is this normal? or is regulator damaged? will it be fixed if I replace it with new one? what should I do to get constant 9v output without modification at relay side?
when no relays are energized output voltage is nearly 9v. when one relay is energized voltage drops to nearly 7v. and when both relays are energised voltage drops to nearly 5v. each relay is driven by bc547 transistor with 1k base resistor. is this normal? or is regulator damaged? will it be fixed if I replace it with new one? what should I do to get constant 9v output without modification at relay side?