The E1T tube is a marvel of the vacuum tube era. It was over 40 times faster than the dekatron tube and displayed the result directly. The E1T tubes were used mostly in scalers used in nuclear physics research . If you want to learn more about the tube check this page : http://www.dos4ever.com/trochotron/TROCH.htmlThe tube needs a bit of electronics to work : the reset circuit and the bias and feedback circuits . It also needs high voltage (300V) and the heater voltage (6.3V) . There are several designs of the E1T tube testers on the internet , but all of them require powering them from external , high voltage power supplies. To make it a bit simpler I designed a self contained tester which has all necessary electronics on one board. All it needs is a 20-24V DC power supply.
Wow, this is cool, vacuum tube technology I had not heard of before. I will enjoy reading the background information on this technology on a slow day at the office.
Had some difficulties when building this tester. First one was (as expected) the HV voltage converter. I had to replace the MOSFET and the diode by parts with significant better performance ! Additionally, I had to reduce the converters switching frequency from 200kHz to 100 kHz. Then the 300V were stable and I could see idle cycles from the MC34063 which means there is some margin in current that it can deliver. Next thing was : the tube stopped counting at 9 ! The reset did not work. So I've removed the 2 1N4148 diodes and now everything works as expected. For the PCB development some hint : please use thermal pads next time. Soldering of pads which are completely inside copper needs too much power.
And why are you using 555 in this tiny package without any reason? I had problems to buy the 2x 555 in this package. Reichelt had only 1 part and they sent the 2nd one some days later ;-)
Current consumption is in my case 0.19A at 24V input. I would recommend to use 6V as input voltage (which can be taken from 4 x AA batteries) and then use 2 high efficient boost converters from 6V to 15V and from 15V to 300V (cascaded). This can reduce input power from 4.5W to 3W. But OK, its only a tube tester...
I cant solder smd
can I pay somone to make one for me