Please explain the circuit diagram!?
Hey everyone,
Below you will find a circuit diagram that I am currently struggling with…
What does it do? It's supposed to be at 17.5V. Can you tell me the purpose of the individual components and also calculate the required voltage?
The blue does not need to be considered
(0 rating, 0 votes, rated)You need to be a registered member to rate this.
Loading...
Above the left to the right: diodes as polarity protection, Zener diodes against overvoltage (but not a fuse, well…), interference suppression measures (HF filters), then go right out to "1PS24V", then there are more circuit parts hanging there, the name suggests that there are 24V to be expected.
Bottom (left n. right): Voltage divider 20:1 presumably for voltage measurement at "U1_OK" at another point, then voltage divider with Zener diode, which breaks through only above 15V + 2x 0.75V base voltage yields approx. 16.5 V input voltage from which the transistor becomes conductive and pulls USP_5V to low.
Supplement:
17.5V aren't here.
Normally, 24V supply voltage is fed to the connector X1, and the lower part is used for voltage monitoring. At U1_OK, 1.14V should be measured (at 24V at the input), USP_5V is 5V if the input voltage is below 16.5V and becomes 0V if the input voltage is > 16.5V. For 24V input voltage, 0V must be measured at USP_5V.
And actually, the forward voltages of V1, V7, V189 are added, so that the indication 16.5V is probably not quite accurate, and the threshold for USP_5V then goes rather towards 17.5V…18,5. By chance you're asking exactly after 17.5V?
Thank you
I'd think it's a stabilized and undisturbed power supply.
Interesting "Switching power supply" without "Switch"…