So here's the latest.? My thought is that this would more or less replace the existing plug on the radio.? Can't really do that inside the radio without a lot of effort.? Here you would just plug in the board into the existing plug, which means you can now
only plug power into the board. The enclosure would have some sort of lid, but I haven't drawn it yet.? It uses a single existing screw from the bottom of the case to keep it from getting torqued too much when you unplug.? The box would need to be 3D printed,
it's a bit awkard and needs way more support that I'd like, but it's pretty small, so shouldn't be too bad.
From Left to right:? F1 would be a 10A fuse. D1 is a TVS diode to filter out fast high voltage transients (ESD protection).? The middle section (C1 to D3) is a crowbar overvolt circuit.? When voltage is below 16v, no current goes through these devices.? The
gate to the SCR is at 0V, so nothing happens.? When voltage is above 16v, the zener D2 allows voltage to pass, which turns on the gate on the SCR.? The SCR then creates a high current short to ground, which then pops the fuse.? Caps and ferrite for filtering
so you don't induce a current and pop the fuse from RF. Next section is reverse polarity protection.? After some going back and forth, I've picked a mosfet that is very low Rds, (1.6mOhm).? If power is connected with the correct voltage, it passes the current
with only a maximum power loss of 0.16w.? If polarity is reversed, Vgs will be 0v, and the mosfet won't turn on, no voltage at the output.
So you get ESD, overvolt, overcurrent, reverse polarity protection with no voltage drop at very low power loss.?
Let me know if I've made any major mistakes here.? I figure I'll make a short run of boards to test and verify I didn't mess up the board design.? If that's all good, then I'll run do a larger order and put them up for sale on the etsy page.? Downside is that
this process could take a month or so.?
Jeff
Andy,
if you have already brought up the topic here, I will answer here, although the title of the topic does not indicate this. I, who am only a radio user and cannot code, am told by others that it is not too late to learn. The sBitx developers settled on Discord
because many other devices are discussed in this forum. Besides, you also know that the direct answer option is given there, not here. In this way, developers can immediately find the questions that concern them and can answer them. So it is not so easy to
distinguish between the two servers, because each has advantages and disadvantages, you just have to consider them.
Just as no two people are the same, no two thoughts are the same. You can be confrontational and you can come to an agreement.
It is not necessary for everyone to go there, anyone who is interested in the matter and has an idea to share can do so.
--
Gyula HA3HZ
