Full Member level 3
i have built a pcb with an atmel tiny2313 which drives a few relays. the mcu drives the relays through the 2N3904 transistor. parallel with the relay's coil a 1N4148 diode and a 1k resistor with a led are connected. the power supply of my circuit is 24V. The problem is that, without the mcu on board the leds of each relay are always on. what is going wrong?