Electronics > Beginners
How to set reference for a sine wave with dc supply
exe:
Sorry, can't follow the schematic. It's not drawn a conventional way. Like, inverted T3 that has GND on top makes it hard to read. Or single +5V port used for all the connections. R23/R23 divider drawn in a very strange way making it hard to see it's just a divider. The picture is also too small so some symbols not readable.
anishkgt:
Hopefully this should be better.
anishkgt:
Well, things are never as it seem on a computer simulated environment than in real life.
I just got the boards made, soldered them and they don't seem to be working as i thought it would. I checked to see the ac voltage it is 33vac and at pin 4 (Non-inverting pin) the voltage does not change when there is a voltage drop at the ac line. The voltage drops to 28vac.
Would it be because of the the filters cap and the diode ?
anishkgt:
--- Quote from: pelule on June 18, 2018, 04:44:56 pm ---Do you want to controle/regulate VAC peak to peak 30VAC (+/-15V referred to zero/gnd)?
So you could use a AC-to-DC circuit - a bridge rectifier (diodes) and a buffer capacitor to convert the AC voltage to a DC level and compare with a comparator.
/PeLuLe
--- End quote ---
That was something I had done but I am not sure if I have the wiring correct. I have the return from the ac voltage divider back to the neutral. Should it be back to GND ?
When I reduce the voltage at the ac I can see a drop in voltage the cap but that voltage cannot be fed in the opamp as it is quite high, 38v. Should I drop the values on the resistors of the voltage divider at the ac side ? I have a 5K trim pot.
Www.Georgehobby.wordpress.com
Equipments: DSO104z, Hakko FX888D, Brymen BM869s
exe:
--- Quote from: anishkgt on June 28, 2018, 10:43:38 pm ---Well, things are never as it seem on a computer simulated environment than in real life.
I just got the boards made, soldered them and they don't seem to be working as i thought it would. I checked to see the ac voltage it is 33vac and at pin 4 (Non-inverting pin) the voltage does not change when there is a voltage drop at the ac line. The voltage drops to 28vac.
Would it be because of the the filters cap and the diode ?
--- End quote ---
Hod did you measure the voltage? Before diode it is AC and normally measured with RMS voltage. After diode it is half-wave and I wouldn't measure it as as AC. Rather, I'd looked at peak value.
Concerning the circuit, I don't understand the whole upper block. Doesn't look right to me. Like, why it uses thyristor and not triac. Or why fuse on live_out and not on live, etc. Why using C3? I think it shouldn't be there, as it rectifies voltage, that's not what you want for peak detector.
But even if it was needed, it should have been placed after resistor divider. This way it can be much smaller, smaller voltage rating, and less current through diode.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version