|
Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets. |
|
Thread Tools |
29th Nov 2018, 1:31 pm | #1 |
Pentode
Join Date: Oct 2009
Location: Holbeach, Lincolnshire, UK.
Posts: 134
|
Parmeko P.M.A Mark 2 transformer help needed.
Trying to gather bits together to build a power supply for an R1155. Saved this transformer out of an old valve based oscilloscope as logically thinking it ought to have the correct voltages in there somewhere for the heaters and HT. Can't find any info online or a schematic for the scope and probing around with a meter isn't getting me anywhere....Scope was an old Solartron 1400 (did work recently but nobody wanted it). Other than Parmeko PMA Mk2, Parm 51 and 301060170 there isn't anything else to identify the transformer.
Inputs are not an issue as it is "as removed" complete with the input voltage selector panel and mains lead still attached. There are 16 output terminals on the top, i have tried probing adjacent pairs and opposite pairs but not really seen anything sensible (don't seem to have 6.3v anywhere). They are numbered but don't really follow a logical pattern. |
29th Nov 2018, 2:06 pm | #2 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
|
Re: Parmeko P.M.A Mark 2 transformer help needed.
So far as I can make out:
11-12=155v 13-14=46v 15-16-17=0v-100v-1,000v 18-19=6.3v@3.5 amps 20-21-22=14v-0v-14v 23-24=6.3v@2.5 amps 25-26=6.3v(CRT Heater?) The above from the CD1400 manual at Elektrotanya Lawrence. |
29th Nov 2018, 2:53 pm | #3 |
Pentode
Join Date: Oct 2009
Location: Holbeach, Lincolnshire, UK.
Posts: 134
|
Re: Parmeko P.M.A Mark 2 transformer help needed.
Thanks for that, sussed it now. After some head scratching I found the neutral had been snipped off...Doesn't seem it will be any good for my R1155 though which is frustrating. Oh well the search continues.
|
29th Nov 2018, 9:10 pm | #4 |
Heptode
Join Date: Jan 2009
Location: West Lothian, UK.
Posts: 761
|
Re: Parmeko P.M.A Mark 2 transformer help needed.
Just to add that the 155 volt winding fed a 2 diode voltage doubler to provide 360 volt HT(320v decoupled) at about 240mA.
A negative 56 volt rail could provide 170mA and the -16 volt rail 330mA. Total consumption up to 200VA. And a large thump when switching on at wrong part of cycle...
__________________
George |
30th Nov 2018, 7:23 am | #5 |
Dekatron
Join Date: Jul 2009
Location: Sleaford, Lincs. UK.
Posts: 7,662
|
Re: Parmeko P.M.A Mark 2 transformer help needed.
Scope tfmr's often have dual primaries at least, so need jumpering. You're not too far away so your welcome to rumage through my tfmr stash if it helps or if it comes to it borrow my coil winder and wind your own.
Andy.
__________________
Curiosity hasn't killed this cat...so far. |