I've been doing my own PCB designs for the past 10+ years, and the main areas to look out for are:
1. Trace-width for higher currents. There are online calculators for this, but they seem to undersize the conductors based on my gut feeling so I use them as a reference and make mine stay a lot fatter. The most I put on any trace is 2 amps, and for that I use conductors 0.25 inches wide. Be aware that feedthrus have much higher resistance, so use redundant feedthrus when possible. I do the complete power-routing first, before any signals are routed. 2. Spacing for higher voltages. Again, look for online calculators/table for creepage and clearance. There are various factors that affect spacing including pollution levels. I always pick the most conservative rules I can find. Spacing for 500V or less is pretty small, around 2mm. 3. Trace-lengths at higher frequencies. Traces are additional inductance and resistance, so if you have frequencies in the Mhz region or higher, you need to be careful about routing these signals. Generally best to keep them as short as possible and minimize bends and feedthrus. Often you will need to waste some PCB area for optimum component placement to minimize the lengths of critical signals. These should be routed after power/gnd is done and before the other signals. 4. Noise and ground loops. I dont do any precision analog designs, so I cant offer much help here, but there are a lot of good online articles on how to avoid ground loops and minimize noise coupling. I use a lot of bypass caps on my boards, and I've never had any problems with logic glitches. Generally, if you have a single power supply, it's best to run separate power and GND traces to the noiser/higher-current sections, then bring them together at 1 point. On a recent project, I have a rather noisy DCDC converter, so I routed separate PCB traces for its power and GND, and the design works fine. On Tuesday, September 13, 2022 at 10:23:37 AM UTC-7 nixiebunny wrote: > Hi. I am certain that my scope clock designs were some of your > inspiration. However, it is impossible to see what your circuit looks like > because the schematic diagram does not show the transformer windings, and > none of the transistors are shown as transistor symbols. Also none of the > chips are labeled with part numbers. > I recommend that you take some time to draw the schematic clearly. Then > design a PC board with only the power supply and CRT portions to test those > first, before trying to add the computer to it. > It will probably take months for you to get it working well. At least it > did for me. I had to learn a lot about power supplies and transformer > windings and so forth. > > > On Tue, Sep 13, 2022, 7:30 AM WawaPL <[email protected]> wrote: > >> Hi everyone, >> I wanted to build scope clock for a long time now and I have managed to >> create this PCB by borrowing bits and pieces from another people's clocks. >> Right now I am stuck at PCB making. Basicaly I am unsure if layout >> is optimal. What is more concerning for me is that I am unsure if I made >> correct circuitry for driving HF transformer. This is my first time using >> UC3524 as driver. If someone could take a look, I would be really gratefull. >> >> -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/55ae2a5d-0167-490a-bde0-6ef12ffb22d3n%40googlegroups.com.
