Microwave Transformer for Inverter plans

[Deleted]

HI Everyone, I'm new on this forum and wanted to say Hi to everyone, no replies required, thanks ;D.
I am looking at Gary's great site ( Many Thanks Gary)and became interested in the Inverter plans. After some reading I realize the microwave transformer size is important to this project.
As I begin to search out a suitable transformer, I wonder about the units that are marked - labeled- at 1000 (or larger)- watts by the manufacturer suitable.
These indicators are on the outside of the package.
I do see these going to the recycle depot and could search for a suitable size.

MAny thanks

Keith

[rmeyn]

I've got to tell you-- as soon as your family, relatives, and friends
find out you are looking for micro-wave transformers, you will find them collecting on the back porch. I know, from experience.
rmeyn

[Gary Lecomte]

As I explained to Keith in an Email, When using MicrowaveTransformers for Inverters, You need to Permentally remove the SHUNT Laminates, as shown here. If you don't, You will get POOR EFFICIENCY, as they cause the transformer to Saturate at higher power.

[Deleted]

HI Again guys, Thanks for your replies. Rmeyn, thanks..I hope that is so.. I live out of town and it is hard to get stuff cheaply these days and being out of town is not great.

Gary and others ; I have found a transformer in my so called collection shed ( junk to my wife ) . It is a bit different from a MOT I think. It is marked TL2 ane 600591 ap. Measures 4.5 l x 4.5 h x 2.25 w . I can see some of the primary an it is a # 12 or 14 coated wire.
It has a schematic on it. 2 wires = 115 vlt, primary, 2 wires = 17 vlts, secondary, epoxy coating
Also, 2 wires P0 + P1, These are a secondary wiring around the primary of a couple strands and not the same wire used in the primary I think , but appears paint of a silver color?
Also, 1 wire coming out of core secondary...I thought was was grnd but I think it is live according to my burnt meter..
Finally, I put a fused 115 AC to the primary and got 86.5 volts secondary.
I put a AC clamp meter across the 115 and one side read 10 .2 amps, the other 4.8.. This transformer has quite a hum to it.
Anyways, if anyone has and idea of what this is or if it can be used for the inverter plan then let me know.
Im fairly new to transformers , but have played around with IC's for a bit.
This link describes transformers rather well www.allaboutcircuits.com/vol_2/chpt_9/7.html

Thanks guys Keith

[Gary Lecomte]

Nov 27, 2008 7:43:22 GMT -8 @keithh said:

HI Again guys, Thanks for your replies. Rmeyn, thanks..I hope that is so.. I live out of town and it is hard to get stuff cheaply these days and being out of town is not great.

Gary and others ; I have found a transformer in my so called collection shed ( junk to my wife ) . It is a bit different from a MOT I think. It is marked TL2 ane 600591 ap. Measures 4.5 l x 4.5 h x 2.25 w . I can see some of the primary an it is a # 12 or 14 coated wire.
It has a schematic on it. 2 wires = 115 vlt, primary, 2 wires = 17 vlts, secondary, epoxy coating
Also, 2 wires P0 + P1, These are a secondary wiring around the primary of a couple strands and not the same wire used in the primary I think , but appears paint of a silver color?
Also, 1 wire coming out of core secondary...I thought was was grnd but I think it is live according to my burnt meter..
Finally, I put a fused 115 AC to the primary and got 86.5 volts secondary.
I put a AC clamp meter across the 115 and one side read 10 .2 amps, the other 4.8.. This transformer has quite a hum to it.
Anyways, if anyone has and idea of what this is or if it can be used for the inverter plan then let me know.
Im fairly new to transformers , but have played around with IC's for a bit.
This link describes transformers rather well www.allaboutcircuits.com/vol_2/chpt_9/7.html

Thanks guys Keith

It Doesn't sound like it was designed to operate at 115 Volts.
Not if its Drawing that current Without a load on the output.

[Deleted]

Gary; I have to agree. I will put it aside for now. The word is out on microwaves for parts. This could take some time.
Is there a web site I can go to easily figure out the windings required for the new 12 volt side that has to be rewound?
Thanks Keith

[Gary Lecomte]

Its Quite Easy.

1) Carefully Remove the High Voltage Secondary Winding.

2) Note: In between the Secondary and Primary winding there usually is a 2 to 3 turn HeaterWinding.

3) With that HV Secondary winding Removed, Than Connect a Small Load to this Heater winding. (Possibly a 2 to 6 Volt Flashlight bulb.)
(This Small load is Recommended to get a More accurate reading.)
Also connect an AC Voltmeter on this heater winding.

4) Plug in the transformer and Measure that voltage across that Bulb.

** Example 1) Now IF it measure 2 Volts and IF it has 2 Turns, That means you need "One turn per volt. (12-0-12 Turns for your inverter Primary.)

** Example 2) If it Measures 3 Volts and it has 2 Turns, it means you need "0.66 Turns per volt". (8-0-8 Turns for your inverter Primary.)

You can also test this out by quickly winding a small wire with that number of turns and measure the output voltage. (Ideally also with a Small Load)

Microwave Transformers are BEST, Because the 12 volt Primary you wind, Gets Wound Directly on the Core. Not Over Top of an Existing winding.

HOPE THIS HELPS!

EDIT: Testing the Red Wires on the Micro-Wave Transformer, PICTURED ABOVE, It has 2.8 turns and Measures 2.8 Volts. So 1 Volt per turn.

[Deleted]

HI Gary; That is a very good step by step..I cant fail on that...I will get back when I am ready for the next step...

Keith