pls help- mosquito racket repair

[takne007]

hello

i joined this forum today. i purchased a mosquito racket. now its not working. please tell me ,how can i trouble shoot this.

 

[forumlicker007]

What exactly happened takne? Is it oscillating or dead?

 

[takne007]

it's not oscillating. so,how do i troubleshoot? transistor is the oscillator,right? there is a transistor.looks like a FET, actually. i don't know how to check a FET. the number is "H SD 965". the transistor is not available.please help.

 

[blueroomelectronics]

Is it under warranty?

 

[forumlicker007]

FET only. Might be a faulty one I guess. Replace it, before that check 1.5vx2 power supply coming to the board or not. Maybe problem with X'former. You've to check it thoroughly.

 

[takne007]

the bat is made in china.no guarantee.pls tell me how to check the transformer.

 

[mneary]

2SD965 is a bipolar junction transistor. You can check it with an ohm meter. Scan this forum for the method.

 

[takne007]

could some one tell me the equivalent of 2SD 965 transistor? there is a transformer(driver transformer i think) in the bat. how to check it? where can i find them?

 

[mneary]

Where you can find them depends a lot on your location and your resources.

 

[takne007]

i live in India.
I have tested the transistor using digital multimeter in diode testing position. voltage between emitter and base is 1.05v and between collector and base is 0.65v. what does it mean that the transistor is bad?

 

[takne007]

for the second time of requesting, what is the replacement for 2SD 965 TRANSISTOR?

 

[mneary]

That means the transistor is probably good.

Not knowing the exact circuit, if a TIP31 fits (I know it is bigger) I would try it. The gain is not the same but the circuit is probably a blocking oscillator and wouldn't care.

I don't know what transistors are commonly available in your town, but now that you have said you are in India, perhaps one of the forum members who can help will speak.

 

[takne007]

so, the transistor is good.then,please explain,why it is showing 1v between emitter and base,instead of .65 volts drop. may be the problem with the transformer. pls tell how to check it.

 

[mneary]

I said the transistor is probably good. With some transistors 1.0V is close enough to 0.65V, others it is not. Also check between E and C.

To check the transformer, identify the windings and check continuity. This is probably fruitless because the problem could be high voltage arcs that only appear when it is trying to operate.

To proceed further you probably need to reverse engineer the circuit. By this time I would be buying a new one and taking this one to e-waste disposal. But that's just me.

 

[audioguru]

Look at Mosquito Repeller in Google. Those ultrasonic noise makers do not repel mosquitoes. Your government needs to put larvacide in every pond and rain catch basin like mine did. Now all the mosquitoes and the bats that ate them are gone.

 

[mneary]

Uncle $crooge, look at Mosquito Racket in Google. It's a zapper in a tennis racket that you wave at mosquitoes. Equally pointless, but a lot more fun.

 

[audioguru]

The history of the extremely cheap Mosquito Racket zapper shows that they either do not work or they fail in a few days.

 

[Sceadwian]

For every one you kill 9 others will bite you anyways.

 

[takne007]

i use a liquid mosquito repellant. my goal is only to study and understand the circuit. i want to turn that thing into a stungun, with some multiplier circuits of course.

 

[Hayato]

Multipliers circuitry are very unefficient and have very high impedance output.

You racket have a very low current output and if you add a a multiplier circuit it will become useless.