not as long as you connect them so that voltages add up instead of subtract...
testing of power traffo........
short circuit testing to determine copper losses at various input currents...
this traffo has a core rating of over 1000va, will supply a continuous power of 250 watts,
and about 300 watts at full tilt, so i made it big to keep the heat down hopefully...
short circuit testing to determine copper losses at various input currents...
this traffo has a core rating of over 1000va, will supply a continuous power of 250 watts,
and about 300 watts at full tilt, so i made it big to keep the heat down hopefully...
Attachments
H18/M24 is core grade, M3/M6 being of the higher grade, in manila,
the lowest grade H50 is most commonly used in cheap power traffos,
good for solid state amps, but for tubes, you need to make them really big...
short circuit testing is an engineering process to determine copper losses
of a given traffo when rated current is flowing in the primary winding...
for this you need a variac to adjust input voltage so that rated current
flows in the primary winding...i tested this amp for 1 to 5 amps of
primary current with 230 volts this is 230watts, 460 watts, 690 watts,
920 watts and 1150 watts...
voltage readings were taken off the homemade tester i constructed for
taking voltage and current readings, as shown has two ranges that
can be selected by toggle switch...
for the 1 to 5 amperes of test currents, voltage readings were: 8.5v,
14v, 19v, 25v, 32v....
so then copper losses were 8.5W, 28Wm 57W, 100W and 162W...
btw, prior to testing, all secondaries(except the center taps) were stripped and connected to form a short...
this completes the short circuit test...
before this i also did a core loss test, or other calls as an unloaded test...
here, using a kill-a-watt tester, i found that 15volt amperes are drawn
and that 10 watts core loss was measured....
so armed with the knowledge of losses, this traffo efficiency can be calculated..this traffo will supply about 250 watts of continuous power
idling and at full tilt around 350+ watts will be supplied by this traffo...
efficiency, E= 350/(350 +10+28) =90%
i can make a traffo with much greater efficiency than this, but for now
i think this will be just okey...
Attachments
i need an isolation trafo for my hobby, i decided on one, two secondaries,
one is good for over a hundred watts(for testing equipment)
and the other for over 1kw of load power...
core is H50, 2 inch CL by 5 inch stack and weighs in a hefty 38 pounds...
when fully assembled will be on caster wheels....
one is good for over a hundred watts(for testing equipment)
and the other for over 1kw of load power...
core is H50, 2 inch CL by 5 inch stack and weighs in a hefty 38 pounds...
when fully assembled will be on caster wheels....
Attachments
testing for core loss prior to varnish application....
completely submerged in insulating varnish,
soak for over an hour, lifting and then dunking several times,
letting it drip off excess varnish, and then sun drying for over a week....
completely submerged in insulating varnish,
soak for over an hour, lifting and then dunking several times,
letting it drip off excess varnish, and then sun drying for over a week....
Attachments
that wire looks very thick, is it for testing solid state stuff, would tube equipment need such thick wire apart from heaters etc ?
that is a good thing about the Phils, I would never in a million years be able to source a
2-litre [?] can of insulating varnish where I live and if I could it would be very expensive.
you have so much iron lying around you must feel like you are living in a scrapyard !.
that is a good thing about the Phils, I would never in a million years be able to source a
2-litre [?] can of insulating varnish where I live and if I could it would be very expensive.
you have so much iron lying around you must feel like you are living in a scrapyard !.
isolation traffo rated for about 1500 watts secondary continuous.....
there are a lot of metal recyclers here, scrapped electronics from
overseas are exported to the philippines and torn down, precious metals
like gold and silver and copper and aluminum are sorted out and collected,
and then sold for reprocessing, that is how we get a lot of those EI's that others in
other parts of the world can only look at with envy.....
the air drying varnish cost 460 pesos (U$10) per gallon,
i keep a couple of gallons on hand at any given time.....
that vacuum pot is a future project, will get it eventually...
there are a lot of metal recyclers here, scrapped electronics from
overseas are exported to the philippines and torn down, precious metals
like gold and silver and copper and aluminum are sorted out and collected,
and then sold for reprocessing, that is how we get a lot of those EI's that others in
other parts of the world can only look at with envy.....
the air drying varnish cost 460 pesos (U$10) per gallon,
i keep a couple of gallons on hand at any given time.....
that vacuum pot is a future project, will get it eventually...
tony can you supply the manufacturer's details and part number of that air drying varnish so I can look it up online ?
also what is the mimimum ambient temperature needed to dry the varnish.
I am considering buying a second hand electric oven for baking etc.
why have you not bought a vacuum pump before now ?
is it one of those pumps they use for air-conditioning ?
I see people on youtube using them for de-gassing resin etc.
Is that where you got the idea ?
also what is the mimimum ambient temperature needed to dry the varnish.
I am considering buying a second hand electric oven for baking etc.
why have you not bought a vacuum pump before now ?
is it one of those pumps they use for air-conditioning ?
I see people on youtube using them for de-gassing resin etc.
Is that where you got the idea ?