Dear Sirs,
I have an old Compu-aire air conditioning unit that has a little sensor
board in it that measures the temperature and humidity from which a computer board decides what to turn on or off to control the server
rooms temperature etc.
The board has a wire coming off for the temperature, and a wire coming off it
for the humidity.
The temperature wire reads 22 VDC . . . and when I flip the fluke meter to AC
volts it gives me 20 Vac.
The humidity reads about 5.6 Vdc . . or 32 Vac.
A similar unit that is running good has similar readings.
Can anyone explain to me why there is both ac and dc signal voltage levels
in this thing?
And, the little sensor board is powered by 24 Vac.
Poet.
I have an old Compu-aire air conditioning unit that has a little sensor
board in it that measures the temperature and humidity from which a computer board decides what to turn on or off to control the server
rooms temperature etc.
The board has a wire coming off for the temperature, and a wire coming off it
for the humidity.
The temperature wire reads 22 VDC . . . and when I flip the fluke meter to AC
volts it gives me 20 Vac.
The humidity reads about 5.6 Vdc . . or 32 Vac.
A similar unit that is running good has similar readings.
Can anyone explain to me why there is both ac and dc signal voltage levels
in this thing?
And, the little sensor board is powered by 24 Vac.
Poet.
