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Equipment Repairs => DVD/VIDEO/Home Cinemas/Hi-Fi/Mp3/Camcorder => Topic started by: Turnip on November 21, 2018,11:16:33

Title: Ever Ready Sky Baby - Power supplies.
Post by: Turnip on November 21, 2018,11:16:33

Hi folks,

Have a nice one in, where would like to sort 90v and 1.5v from maybe 4 C cells using an inverter rather than heaps of 9v batteries in series.

Had a look on Ebay but buck converter modules rarely give more than 30v with a 4.5v input, so thinking of a few turns on the buck coil, rectified and added to the output.

Gather set only needs 15m/a at 90v so less than a couple of watts.

Wonder if anyone has had a try ? - Chris.

Title: Re: Ever Ready Sky Baby - Power supplies.
Post by: astracat on November 21, 2018,15:23:58

hi turnip
may be this doubled up might do it
https://www.maximintegrated.com/en/app-notes/index.mvp/id/3425

old car used a valve radio but it used a vibrator pack if remember it was quite good
regards
astracat

Title: Re: Ever Ready Sky Baby - Power supplies.
Post by: Turnip on November 22, 2018,11:33:40

Hi Cat,

You're going back a bit to the self rectifying vibrator pack or the OZ4 cold cathode rectifier thingy. Fixed some in the late 50's, and they were horrid.

Even worse were car radios using valves with a 12v HT and a Germanium OA or AD -XXX something or other for output.

Feel that radios using the 'Dxxxx' series valves economical and nifty.

Many thanks your for interest, checked download, but I need 15 M/A at 90v - Chris

Title: Re: Ever Ready Sky Baby - Power supplies.
Post by: astracat on November 22, 2018,16:07:26

hi turnip
showing our ages ha ha ,brought up on valve stuff and lighting fags on eht anode cap sparks ,remember pl509 where cathode resistor went o/c with lack of width,any way will keep looking for you maybe with a cocroft multiplier on output
good luck
astracat
ps this is a circuit designed for this 90 volt battery converter using 5x1.3 v battery including charger circuit
http://www.dos4ever.com/battery/final.pdf

Title: Re: Ever Ready Sky Baby - Power supplies.
Post by: Turnip on November 23, 2018,11:49:17

Thanks 'Cat'

Recall used to light fags from the Ferguson jelly pot LOPT. Only issue was when I tried re-light one after lunch, fag being a bit damp.

Thinking Cockroft/Walton, Chris Cockroft popped by with a mend a few weeks ago. Didn't know him from Adam, but he soon

sorted me about nuclear fission and stuff leaving me more confused than ever.

Have a nice picture of the Cockroft family where Chris is the young lad on the right. Just my age - Chris.

Title: Re: Ever Ready Sky Baby - Power supplies.
Post by: astracat on November 23, 2018,13:51:09

thanx for that ,also remember those jellypot chassis with some horrid faults on also some early sony with thyristor in line output stage talking about fergy ones with 9volt stage refused to work as guy i knew used to put a pp3 battery in which guaranteed him a repeat repair few months later to replace the pp3
battery,could write a book about early repairs ,quite funny.anyway thanks for photo.,90v inverter seems interesting circuit maybe build one one day just to test i wonder if a 150 watt 12volts to 240 would work with just 6volts  in may be an experiment one day
regards
astracat

Title: Re: Ever Ready Sky Baby - Power supplies.
Post by: Turnip on November 24, 2018,11:54:04

Hi Cat, Recall the Sony one as a 'gate turn off thyristor' where it didn't, so used a BU208 though had to snip the heat sink about a bit.

Like your inverter, but seems the 8 pin drive chip is a 12f675 M/Proc needing programming beforehand.

Checked on line, and confused although seemingly our grand kids sort 'em every day using blackberries.

Tend to turn blackberries into wine, myself - Thanks again - Chris.

Think attach a recent piccy of Chris Cockcroft and his four sisters.