Hi
Am making a light break detection sensor as per attached schematic.
Question: I can't find a 5v relay with a coil resistance of 125 Ohms, I have some 5v relays at 70 Ohms would they work ?, also the diode 1n4004 , I have some 1N5397 would they do in place of the 4004 ? .
At 5 volts, the 125 ohm coil will draw 40mA. A 70 ohm coil will draw 72mA. As long as your transistor has a current rating higher than that, and has enough gain to sink that current, you will be fine.
At 5 volts, the 125 ohm coil will draw 40mA. A 70 ohm coil will draw 72mA. As long as your transistor has a current rating higher than that, and has enough gain to sink that current, you will be fine.
Hi again
Is there some way to introduce a time delay into this circuit, so that after the object passes through the beam break the relay will stay activated for lets say a second later !.
A longer time ago I've realized that with an simple REED Contact.
The Power line to the Bulp was wrapped a few times around the reed contact - Dependend from the drawn current.
When Current to the Lamp was drawn the Contact opens.
When Lamp defect no current was drawn and the control Led lights up.