Altafhal
Member level 2
24v emitter follower
Hello friends
i have a problem. I am interfacing a proximity switch with plc. The switch is NPN. When it detects an object it gives me 0V at output and when there is no object it gives 24V or 12V depending on its input voltage. This sensor takes 24V and 12V at its input. I used an inverter to take 12V or 24V at its output. I used 2SA684 PNP transistor and biased it as followed.
I select Beta 250 and by calculation Rb is 100k. This trasistor operates a 12V, 400 ohm relay.
I want that the signal at base should be 5V. How i should acquire this five volts from 24 or 12V.
I have to use 7805, Zener volt diode(if any) or to use 12V at sensor input and use the voltage divider bias to operate the relay.
Please friends reply me soon.
Thanks
Hello friends
i have a problem. I am interfacing a proximity switch with plc. The switch is NPN. When it detects an object it gives me 0V at output and when there is no object it gives 24V or 12V depending on its input voltage. This sensor takes 24V and 12V at its input. I used an inverter to take 12V or 24V at its output. I used 2SA684 PNP transistor and biased it as followed.
I select Beta 250 and by calculation Rb is 100k. This trasistor operates a 12V, 400 ohm relay.
I want that the signal at base should be 5V. How i should acquire this five volts from 24 or 12V.
I have to use 7805, Zener volt diode(if any) or to use 12V at sensor input and use the voltage divider bias to operate the relay.
Please friends reply me soon.
Thanks