View Single Post
Old 9th Oct 2021, 9:44 pm   #8
dalekmoore2007
Pentode
 
Join Date: Aug 2008
Location: Melbourne, Australia
Posts: 201
Default Re: 5FP7 project starting with the focusing coil.

Quote:
Originally Posted by AdrianH View Post
A bit of lathe turning making two formers from Nylon bar and winding two deflection coils for DC testing. the next step would be to get all the gear out to obtain the voltages again. I need to come up with a simple means to get variable EHT, 2 to 6 KV. 250 Volts and -50 volts. But until I figure things out that is a way off.
Attachment 243038Attachment 243039

I will give it a try and see how the deflection goes.

Adrian
Adrian on my sstv build i used a Chinese bug zapper it out puts about 7kv clean DC with a lm317 variable HV worked for me
Another idea if you are using mains transformer for the ac side of it put one the transformers Ac windings in series with a tiny mains ac transformers primary in series with it ..you can control the ac output by the tiny transformers secondary as a magnetic amplifier so varying the ac to the multiplier.....when the secondary is open you get a lower voltage out of the tiny transformers primary ...if shorted full voltage out so very safe ...using high wattage resistors across the secondary you can control what you want the ac out put to be you could also use a light globe to with a resistor
a lot of video and information show dc controlling the transformer but this case you can get a nice range without it ,

https://www.youtube.com/watch?v=DBX1-POuJMw

Btw i used the bug zapper idea on this monitor as well
http://www.taswegian.com/NBTV/forum/...hp?f=15&t=2436
Attached Thumbnails
Click image for larger version

Name:	IMG_0028.JPG
Views:	51
Size:	100.9 KB
ID:	243047  

Last edited by dalekmoore2007; 9th Oct 2021 at 9:51 pm.
dalekmoore2007 is offline