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KF4SQB

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About KF4SQB

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  • Birthday 03/31/1976
  1. LostViking, I said that, if you had read my entire post. To answer the rest of the original question, "S7" would enable you to 'disable' "RL7" by opening it's common connection, thus preventing it from operating. Also, yes, relays are sometimes rated by the resistance or reactance, both measured in "Ohms", of their coil. Use Ohm's law to determine what resistance/reactance can be used at what voltage levels.
  2. The dashed lines indicate that two sets of contacts operate "together". In other words, looking at the "appliance#7" part of the circuit in question, the contacts on the right and the contacts on the left are part of the same relay. For instance, both sets of contacts in a DPDT relay. The dashed lines going from the coil of "RL7" to the contacts above it are to signify that those contacts are operated by that coil, if I'm not mistaken. As for the "N" and "PH" at the lower right, I believe they would stand for "Neutral" and "PHase".
  3. Does anyone have a schematic of the "Tenna" Phase III PS-20 power supply? If anyone has a schematic for a Pyramid PS-20 supply, it may be the same. This unit is a 120 VAC to 13.8 VDC @ 17A continous (20A surge) power supply with no crowbar or other "protection" circuit. Just a "plain Jane" regulator circuit using 3055 pass transistors and an ECA723E regulator IC. I'm pretty sure the '723 is bad, but would like a schematic to do some more detailed troubleshooting.
  4. That's a good question. I wouldn't have thought that only 3 volts over would've hurt them, but it is possible. A good question at this point is what is the actual, not the rated, output of each power supply? Since you're 12v supply is regulated, it will put out 12v. If the 15v supply isn't regulated, it could be putting out as much as 20v open circuit. Also, what "type" of current is the camera rated for? If it's intended for an AC input, and DC was applied, or vice-versa, it may very well have damaged it.
  5. Thanks for the reply. I do have the regulator heatsinked, but maybe not enough. I'll try removing L2, and adding the bypass caps mentioned, and see if that helps.
  6. Hi, everyone. I've been keeping an eye on the main board for a few years now, but just signed up for the forum. I'm now wishing I'd done this earlier! Anyway, here's my problem: I'm trying to design and build a circuit to use a 5-bit binary input to drive a dual seven-segment LED display. I'm using a TO-220 package 7805 regulator for power, a 28F010 Flash EPROM for binary to BCD conversion (overkill, I know, but it's what I had laying around), and a pair of HD14511BP ICs to handle BCD input and display drive. My problem is that the 7805 gets way too hot, despite the fact that it's load is nowhere close to it's max output, and the display flashes "00" over and over, very fast, no matter what the binary input is (possibly a bad program in the PROM, as I'm no programmer ::) ). If anyone wants to see the program in the PROM, ask me and I'll email it to them, as I have no way to host it for download, or just write a new one and send me. I want the display to show "01" for binary "0", numerically sequential through "32" for binary "31". Here is the circuit (the pin numbers for the display module are incorrect in the schematic, but the "names" applied to the pins are correct):
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