RobertISaar
New Member
... i see it's a common question recently, went through all of the popular ones but couldn't find a situation that quite matched mine...
anyways, another project for me, one i can't quite wrap my head around how to complete.
have been trying to figure out how to divide an A/C signal into half of it's original frequency. original frequency can reach up to 3,500Hz and in the area of 100 volts (not sure if peak or RMS, simulating it as peak).
been attempting to make a circuit that will feed into a 40175 to do the divide, but i can't seem to get rid of a significant negative voltage(-96V) when i run the design through multisim. the output of the 40175 looks perfectly acceptable(which i'll convert back to A/C via a .01uF cap), but i'm nervous about connecting the gate of a 2N2222 (or any other common NPN transistor) to that kind of negative voltage...
i get the feeling that i'm missing something really basic(pullup or pulldown?) to get rid of that negative voltage. or if it's even an issue?
anyways, after this issue is solved, i'll likely redo the dividing portion of the circuit eventually so that dividing by something other than 2/4/8/etc are possible, since that would make the circuit incredibly more versatile. probably one of the ATTINY units would be more than sufficient using a couple of pots to setup the division ratio of a timer.
here is the current circuit(with just rough values to at least get it functional):
**broken link removed**
and the results it produces:
**broken link removed**
perhaps it's because i'm entirely new to it, but i can't figure out how to color the traces differently... but there is a nice 15V square wave at half the frequency of the signal that is driving the transistor. with the resistors currently used, it's peaking around .79 volts, but that big negative dip to -96V isn't even visible on the display without shrinking it all down and killing any definition of the rest of the signal.
anyways, another project for me, one i can't quite wrap my head around how to complete.
have been trying to figure out how to divide an A/C signal into half of it's original frequency. original frequency can reach up to 3,500Hz and in the area of 100 volts (not sure if peak or RMS, simulating it as peak).
been attempting to make a circuit that will feed into a 40175 to do the divide, but i can't seem to get rid of a significant negative voltage(-96V) when i run the design through multisim. the output of the 40175 looks perfectly acceptable(which i'll convert back to A/C via a .01uF cap), but i'm nervous about connecting the gate of a 2N2222 (or any other common NPN transistor) to that kind of negative voltage...
i get the feeling that i'm missing something really basic(pullup or pulldown?) to get rid of that negative voltage. or if it's even an issue?
anyways, after this issue is solved, i'll likely redo the dividing portion of the circuit eventually so that dividing by something other than 2/4/8/etc are possible, since that would make the circuit incredibly more versatile. probably one of the ATTINY units would be more than sufficient using a couple of pots to setup the division ratio of a timer.
here is the current circuit(with just rough values to at least get it functional):
**broken link removed**
and the results it produces:
**broken link removed**
perhaps it's because i'm entirely new to it, but i can't figure out how to color the traces differently... but there is a nice 15V square wave at half the frequency of the signal that is driving the transistor. with the resistors currently used, it's peaking around .79 volts, but that big negative dip to -96V isn't even visible on the display without shrinking it all down and killing any definition of the rest of the signal.
