FloppidyDingo-
Power supply is now finished
11/02/2016 at 00:31 • 3 commentsI have finally gotten the tub to light up, which means the PSU is done and I'm ready to move on.
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Since the tube is miniature, the voltages needed to run it are smaller than a normal tube would take (much smaller than what I was expecting). The heater is running at 5V, if i were to go any higher the dot would fade away after a few seconds. The accelerating anode is at around 50V, and the EHT is around 1500 - 2000V (I wasn't able to get an accurate reading with my multimeter). For now I have the cathode tied to ground, but I will eventually attach it to a transistor for video and brightness control. Here is the entire unit without the case:
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The entire system takes in 12V from a molex connector, and I will also add a barrel jack so the unit can be powered from the wall. Here is a close up of the power supply:
As you can see, the flyback driving transistor needs a fan to keep cool. Without the fan the transistor gets up to 90C, with the fan it sits at around 35 - 40C. There is a thermistor on the heatsink because I'm adding a thermo regulated fan controller, since that thing is noisy stuck at full speed. I also had to add my own primary to the flyback since the built in one is being picky, it might be shorted.![]()
Next up I'm going to work on the cathode control and then the deflection coils. Also sometime soon I'll post schematics of the entire thing, so keep an eye out for that.
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Mistakes were almost made
10/19/2016 at 02:47 • 0 commentsSo i accidentally dropped the CRT and broke it, so i had to go on an emergency trip to the thrift store and bought an old Karaoke machine that sat there for months. It had a new tube i could use, and very lucky of me, It's identical to the other one in pinout and size, so yay! It's like nothing ever happened.
The flyback in the karaoke machine was also easier to figure out than the other flyback I had, so I'm using that one instead. The pinouts were practically given to me. So despite my goof, i should have this thing working soon
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Figured out pins for the electron gun
04/26/2016 at 03:42 • 0 commentsSo I took a look at the electron gun, and the connector attached to it has 5 wires: Red, Brown, Yellow, Purple, and Black. The Black wire is ground, the Brown wire is the heater, the Yellow wire is what looks like the control grid, and the Red and Purple wires look like focusing anodes. And then there's that hole looking thing in the side of the tube where the flyback transformer plugs into. What voltages I need to operate everything, I'll find out next. And then I'll figure out the coil thingies, and start making patterns.
Oops, I got some of that wrong. So the yellow wire is the cathode and i apply a negative voltage to it. The purple wire is the control grid (G1) and I can leave it unconnected for now, but I apply a negative voltage to it if i want to use it. The red wire is the screen grid (G2) and I apply a positive voltage to it. There are more grids in the tube, but they're taken care of for me by the neck board or the tube itself.
