Hi, may i ask you something?
How can you generate a 3 states ( +Vo, gnd -V) signal (kinda RZ signal) (of course the 200Hz pwm'ed signal is not a problem wth a 51 ...) with the following restrictions... only a 3V batt allowed and output must feed 0.5mA max ...
I was thinking about current sources and a 3state switch array (to draw current from +V to the output load, then the 'hiz' state with the load connected by itself to ground and then the -V state with the current flowing towards -V ... (i mean 3 0 -3V)
But i have some doubts about that solution and in the choice of the correct 3V regulator
(i'll upload the schematic of my idea as soon as i can )
best regards
Tuco!
generate a 3 states ( +Vo, gnd -V) a RS232 transceiver with an enable pin
Erik
I like sentences like: "of course the 200Hz pwm'ed signal is not a problem wth a 51..."
You talk about "the 200Hz" like we are expected to know something about it. We don't. We don't know anything besides the information you cover in your posts. We haven't seen your assignment specification.
That was my first thought, but I think it would give you +V, -V, and Hi-Z - not actually 0V ?
Small DC/DC converters are readily available that give +/- bipolar outputs...
It all depends on how strong the signal needs to be held to 0V - if it is enough to have a resistor from the output of the RS232 driver to ground. From what little we know, the speed seems to be quite low, so there shouldn't be needed a strong drive to 0V to handle any cable capacitance at least.