naming components

Discussion in 'General Electronics Chat' started by Zanac-X, Jul 28, 2013.

  1. Zanac-X

    Thread Starter Member

    Dec 23, 2011
    hey guys :)

    i found an old radio/type recorder in the dumpster and won big time,good clean 6V motor ,transformer ,2 loaded PCBs and im very happy

    but i need your help with something here :

    1- the transformer is clean i haven't tested it with my voltmeter until now but i was wondering how will i find the transformation rate if its not written in the case like normal transformer, is there any way other than using a voltmeter.

    2-the other component is a microphone right ? , how can i test it ? , any advice you can give me as i have never worked with one before.

    3- this DC jack (what is the proper name for it ?) has 3 pins and im wondering what the third one does? ,and how the pins are arranged when i want to use it, and if there is a pdf link to it that would be awesome.

    thank you very much :)
  2. WBahn


    Mar 31, 2012
    In theory, if the wires in both windings are the same size, you could measure the resistance and use the ratio as an estimate of the turns ratio. But chances are the wires in the lower turns winding are larger because they are going to handle more current.

    If you measure the relative inductance of the two, you could use the ratio of that as an estimate of the turns ratio. You can do that in a number of ways, including measuring the time it takes for the voltage across a resistor to reach half a particular threshold and use the same resistor and the same threshold on both windings.

    But in the end you are going to need to apply AC power and see. If you can, use another transformer to step the line AC down to a small AC voltage, maybe 6V or so, and apply that. Then, if you get the input/output wrong you are trying to step up the line voltage to some ungodly high value that arcs through your windings or that proceeds to fry things (such as you).

    I'm pretty sure it's a mic and my guess is that it's a condensor mic, but I'll leave it to others since I haven't worked with mics much and I don't want to suggest something that is going to damage it.

    There are LOTS of different possibilities here.

    Measure the resistance between all the various pairs when something is plugged into it and when something isn't. My guess is that it is a DC power cord jack and when the plug isn't in two of the terminals are connected and that they are disconnected when a plug is in there. This allows the act of plugging the power cord to disconnect the batteries.
    Zanac-X likes this.
  3. Metalmann

    Active Member

    Dec 8, 2012
    I've stripped, and played with a lot of old recorders, radios, TVs, and that is a condenser microphone, a transformer, and an AC connection.

    As far as testing and hooking them back up.....look on the Net for Instructibles, or such hacker sites.
  4. MaxHeadRoom


    Jul 18, 2013
    If you want an idea of the va size, go to a site such as Hammond Transformers and compare one of a comparable core (lamination) size.
  5. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    That little transformer looks about 2-3W size, so for a 6v tape player it might be expected to be about 9v out, 250-300mA or so.
  6. vk6zgo

    Active Member

    Jul 21, 2012
    Your picture shows the red & black wires connected to a "figure 8"Mains inlet,so that is the primary.

    If you have the correct power cord,you can plug it into that connector & the other end into a Mains power outlet & read the secondary voltage.

    Be careful not to short the secondary wires while you are testing them,or you will let the magic smoke out of the transformer!:D
  7. Zanac-X

    Thread Starter Member

    Dec 23, 2011
    thank you guys but how about the mic and the DC jack how can i test it