Hi friends.. Please help me find what this component is.!!!!!!1

[ramshkrish]

I took this board from an emergency lamp...

 

[hitman1988]

Hi
obviously it is a transformer , and i guess it used in charging circuit of the lamb

 

[ckshivaram]

the yellow thing is a filter transformer
Thin lamination in them ensure low eddy current loss and are widely used in home appliances, entertainment electronics, microwave oven, emergency lights, adaptors, power supplies, power conditioning, telecoms, ups and information technology products.

 

[ramshkrish]

Thank you for the quick reply..... But there was already another transformer for stepping down.. why need another....??????????

---------- Post added at 19:47 ---------- Previous post was at 19:46 ----------

Grreat guys.. Thanks a lot...

---------- Post added at 19:49 ---------- Previous post was at 19:47 ----------

Can someone post the link of a detailed description about the filter transformer..

---------- Post added at 19:50 ---------- Previous post was at 19:49 ----------

Wil be more useful for me,....

 

[ckshivaram]

Transformers are not usually seen as filters. As their name implies they "transform" things and in most cases it is the level of voltage that is altered. So that the AC from the mains supply (in the US 110-115 volts ac) is put through a transformer and comes out at a lower level for use in the appropriate equipment. (it can of course be used to step up a given voltage in other situations). Some Inductors and transformers share some characteristics such as wire wound on metal but they are different. Your post was asking about filters. Now many pieces of equipment have the following set up. There is a transformer to alter the voltage. Then a rectifier to change it from AC to DC and this is generally followed by some sort of filter to smooth the supply. This is often a capacitor, it can involve capacitors and solid state devices to get accurate levels and some supply filters use inductors and capacitors in combination. It always helps to get the basic principles clear and in this case the best bet would be to check out the two terms in a basic book on electronics.

---------- Post added at 19:54 ---------- Previous post was at 19:52 ----------

Transfomers have internal impedances or reactance that can be a filter to certain frequencies they are not designed to 'transform'. This is basically related to coils of wire, magnetic flux saturation, copper losses, etc.

 

[ramshkrish]

Thanks you so much for your quick reply Mr.shiv.. Got a fair idea of what it is... Will soon get familiar by reading about it.. Thank you once again...;-)

 

[Tahmid]

Hi,
Since this is an emergency lamp, I think that's a ferrite transformer used to step up the battery voltage to high voltage AC at high frequency to drive the fluorescent lamp (I think this emergency lamp is for fluorescent lamp).

Hope this helps.
Tahmid.

 

[ramshkrish]

Ya your right.. It was used for flo lamp... But as per your answer will it invert the voltage back to AC..???????..

---------- Post added at 21:27 ---------- Previous post was at 21:22 ----------

Can you give me the link for FERRITE TRANSFORMER detail

 

[Embedded_Geek]

Dear ramshkrish,

The transformer shown on the picture is called HFT( High Frequency Transformer). For lighting up the tubelight(20 W) we require high frequency supply, so at the output section we need to step up the high frequency supply to little bit more. By the way it step up HFT. The tube is connected to the output of the HFT. Check that out in your circuit for satisfaction.

 

[ramshkrish]

Very much Confused...... Got 4 different answers....In a HFT is there any identification for output terminal, or will i have to analyze the full circuitry...??

 

[Embedded_Geek]

Hold on i'll post the sample circuit diagram for you

---------- Post added at 21:53 ---------- Previous post was at 21:50 ----------

 

[Tahmid]

Hi,
High Frequency Transformer and Ferrite Transformer are the same thing. They are used to convert from AC to AC. In your case, it is a step up transformer. So, its steps up AC converted from battery supply to high voltage high frequency AC for driving fluorescent lamp.

Hope this helps.
Tahmid.

 

[ramshkrish]

Oh ok ok..... I was not aware that the power from the DC battery will get converted to AC before fed into the bulb...

---------- Post added at 00:09 ---------- Previous post was at 00:06 ----------

It was an old emergency lamp and I almost spent 10 years thinking that the bulb works on DC...

---------- Post added at 00:10 ---------- Previous post was at 00:09 ----------

;-)........

 

[Embedded_Geek]

Instead of AC we can use simple pulse also. The 555 timer in the above circuit produce pulses between 0 and Vcc. So that is not AC. " The property of transformer states that a change in current in one coil induces current on the other coupled coil". The direction of current does not change that is why it cannot be said to be alternating current.

 

[bluehole]

It was an old emergency lamp and I almost spent 10 years thinking that the bulb works on DC...

A Bulb Or tube or both???
If it is a Bulb Like Bike headlight or Search light then the bulb gets directly from the battery in your emergency lamp.
If it has a Tube small Tube light kind of thing then it is fed with a high frequency AC.

The thing is a transformer which is a High Frequency Transformer which has a ferrite as its core.
it is needed if the system has a bar/tube light.
The high frequency eases the Ionization of the gas inside the tube and so the tube starts conducting hence glow.

 

[FvM]

The property of transformer states that a change in current in one coil induces current on the other coupled coil". The direction of current does not change that is why it cannot be said to be alternating current.

I would prefer to consider it as a case of AC with superimposed DC current. Interestingly, you can't know exactly about superimposed DC on the secondary because it depends on the tube's ignition voltage and transformer windings ratio. As a first guess, the secondary current will be mostly AC, when igniting the tube also in forward phase of the converter. Then a DC component will be left in the transformer's flux balance. An air gap would help to avoid saturation.

 

[Andy G]

Please trace the circuit and post it here, then it will be easy for us to help you

 

[circuit_freak]

have you got the circuit? please share it here. thanks