Buffer/line driver - null pixel without pixel
- Thread starter RobG
- Start date
Is there a schematic somewhere?
I thought I had some boards but can't find them now. @ukewarrior Did you figure out how to build these?
I thought I had some boards but can't find them now. @ukewarrior Did you figure out how to build these?
Here is what I have done up from the one board I have left. The schematic I just drew up but don't want to remove the capacitors from the board to determine their values as I need this board and don't want to break it.
Guessing these are the datasheets for IC1 and IC2 (not 100% sure though... voltages seem correct and pins line up but that doesn't give me full confidence):
Guessing these are the datasheets for IC1 and IC2 (not 100% sure though... voltages seem correct and pins line up but that doesn't give me full confidence):
Attachments
Not an electronics knowledgeable guy, but they both appear to be power related and not buffer related? This site https://www.elprocus.com/78l05-voltage-regulator/ has a circuit with "a 10uF of ‘C1’ value & and 1uF of ‘C2’ value would be a perfect selection". C1 being input and C2 being output.
The 78L05 data sheet has this note: "All characteristics are measured with a 0.33-μF capacitor across the input and a 0.1-μF capacitor across the output."
This site https://www.utmel.com/components/78...cuit-equivalent-and-78l05-vs-7805?id=431#cat6 has both of those values in various examples. Looks like .33 uF and .1uF would likely fit the use here?
Still haven't found my boards. Anyone have one they can check?
The 78L05 data sheet has this note: "All characteristics are measured with a 0.33-μF capacitor across the input and a 0.1-μF capacitor across the output."
This site https://www.utmel.com/components/78...cuit-equivalent-and-78l05-vs-7805?id=431#cat6 has both of those values in various examples. Looks like .33 uF and .1uF would likely fit the use here?
Still haven't found my boards. Anyone have one they can check?
MartinMueller2003
Supporting Member
Since those boards take regulated DC as an input, and they are not really driving a heavy load, the caps are in more of a high frequency noise reduction role. For that I would be selecting 0.01uf or (at the highest) 0.1uf caps.
If the input to the regulator was straight from a full wave rectifier, then it would need a big cap (10uf or larger) on the input side of the regulator. A 10uf cap is a pretty big beast and there is no such device on the boards I have. I suspect they are both there just as High Frequency bypass caps (0.01uf).
If the input to the regulator was straight from a full wave rectifier, then it would need a big cap (10uf or larger) on the input side of the regulator. A 10uf cap is a pretty big beast and there is no such device on the boards I have. I suspect they are both there just as High Frequency bypass caps (0.01uf).