DIY - Transformer Testing Made Easy

[Amarbir[Lynx-India]]

Guys ,
I Was Clearing Some Old And New Stocked Transformers today .I Had To Test Approx 25 Units of Transformers of different Make And Models ,Voltage From This To That .Well Let Me Teach you Some Cool Testing Tips for The Transformers .

The Short circuit Protected AC Supply

Not Many Repair Techs Understand The Importance of a CVT " Constant voltage Transformer " . This Is a stabilizer That Has a Unique Property .If The Secondary Side Of The Transformer That Gives Out 220 Volts AC If Short Circuited The Device Drops The AC Voltage And Does Not Output anything .Once the short circuit is removed the CVT starts to function .Bingo This is the first device a Repair tech should buy .Now have a look at what i did .

Well I took a Cable That Had IC Test Hooks In One side "Red Is Positive and Black Is Negative " .The Other Side Goes To My 0 ~ 30 volts DC Supply .In this case i hooked the same to the 220 Volts AC Output Of My CVT .A Better Idea Is to Connect a Male Socket To this side By Removing the Male DC Jacks .Something Like This .

Well Once you have understood this ,Please have a look at the Final Transformer Test Jig .Here You See The Picture of the Ic Test Hooks Having 220 Volts AC In the Probe " Be Careful " .The Protek 608 Multimeter Is Also Lying There "One Of The World's Best Meter " .You Also See One Transformer There .

So how do you know which side is primary and which side is secondary .The AC has to be connected to the Primary Side .Well first Have a small Peek At the Transformer i Was Testing .

Setup The Multimeter To Resistance Mode and Test the resistance of both the sides of the transformer .the Side That Has Higher Resistance is The Primary " Ac side " And The side That Has Lower Resistance Is The Secondary " Output Ac side " . In My Case The Primary Winding Resistance Was 1 Kilo Ohm and Secondary Was Just 12 Ohm .Once This Is Done You Should Connect The IC Test Hooks to The Transformer Primary winding And Relax .Have a Peek At The Photo .

Once The Ic Test Hooks Are Connected To The Primary side ,Please Setup The Multimeter To Ac Voltage Mode And Check The Voltage On the Secondary Output Of The Transformer .In My Case It Was 19 ~ 20 Volts .

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[Teja]

Thanks for the photos. Very helpful.

 

[Amarbir[Lynx-India]]

Thanks for the photos. Very helpful.

Hi ,
There Have Been So Many Ups and down with me but i am bouncing back slowly ,hope to give you more quality electronic and repair tutorials .

 

[chandranariyandath]

Dear Amar bir(Lynx India),I read u r Transformer testing&was interesting.Kindly help me to get CIRCUIT DIAGRAM of one old model MURPHY TRANSISTOR Classic No:1405 all sliding with 4 bands inbuilt Eliminator of 7.5 Volts D.C.Battery facility&7.2 V.DC socket etc.Kindly at least inform me where I will get one copy of Circuit diagram of that murphy Transistor 1405 model of 1975-76(indian make only from Eastern Express,mumbai address).Plz send information to my e mail address [email protected] thanks (chandran)10-6-12

 

[Amarbir[Lynx-India]]

Dear Amar bir(Lynx India),I read u r Transformer testing&was interesting.Kindly help me to get CIRCUIT DIAGRAM of one old model MURPHY TRANSISTOR Classic No:1405 all sliding with 4 bands inbuilt Eliminator of 7.5 Volts D.C.Battery facility&7.2 V.DC socket etc.Kindly at least inform me where I will get one copy of Circuit diagram of that murphy Transistor 1405 model of 1975-76(indian make only from Eastern Express,mumbai address).Plz send information to my e mail address [email protected] thanks (chandran)10-6-12

Hello ,
My New Interest Is Collecting Old/Vintage "Test and Measurement " Tools .I will have no idea of the circuit diagram of the same .Might be some other person on this great indian hifi forum could give you some pointers .I have learned a lot of stuff online and on video for analogue multimeters [ Both in Basic VOM type and VTVM Type ] .I particularly like the VTVM type "Due to its ultra high impedance 11 megaohm .This ancient multimeter can put to shame some of the flukes today [ who do not help boasting lol ] .As india has no people who have interest in vintage test and measurement instruments i possibly would be one of the first once to do this here .Most of the classic and vintage stuff i have learned initially is on hifivision .I am gathering a large stock of them in usa as other then usa there is no place where you can find them in Quantity .Though some quality stuff is there in UK " like avometer" .There could be great vintage test gear in germany and russia also but i have no knowledge of the same .The worst part is the weight of the product .The avometer 8 mk5 is 2.5 kg and its huge .Shipping and handling charges to india from the respective country of origin is extremely high .The volume weight of these is extremely high .Once they reach me my goal would be to restore all of the units ,Stuff in usa is 110 volts and needs to be adapted to indian voltage of 230 volts .In my case i plan to actually change the schematics of the same and indianise it .Lets see how far i can go with this

 

[vivek.saikia]

Its there any way to tell if it is a 220V or 110V primary voltage transformer?

 

[Amarbir[Lynx-India]]

Its there any way to tell if it is a 220V or 110V primary voltage transformer?

Sir ,
You Are Talking About The Primary Side Of The Transformer or some other type like a isolation transformer ?