remote doorbell (buzzer)

either it's wrong, or it relies on threshold Vgs on the MOSFET being very close to 9V also made of unobtanium.

+9V DC | BUZZER | +-------. C | 100R |/ | ---+--------+--| TIP31 | bell \ | |\ 100uF circuit / - E | \ 1n4001 ^ | | / | | | ---+--------+----+-------+-- 0v DC

TIP31 NPN nedium power transtitor was chosen because it can handle 1A through the base with no damage (also cheap and readily available)

--
?? 100% natural

After finally tracking down the image, I notice it still has wires, and no mention of remote access or anything.

Why didn't you give a direct link to the jpg, suitably scaled, rather than that incomprehensible treatise?

Why not just go ahead and spring for a wireless doorbell? You should be able to pick one up for a couple of decabucks at the local home handyman store.

Good Luck! Rich

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ble

.

hooked up to existing doorbell or dooerbells transformer.

s=3D0

will take you right there

IT works, and has been for at least 1 year. (but nobody comes to my door)

I'm sure the circuit can be redesigned using a npn bjt and n channel MOSFET (and a more modern bjt) but I used what was available. I think it's a pretty decent circuit.

Regards,

Simon

close to 9V

I meant the discontuniued PNP

are you sure that's not an MPM ?

the common collector layout would ensure that, but it also puts the emitter at 0 to 1V whch wont't switch the mosfet with that circuit

there's something wrong with the drawing. possibly you've got the MOSFET in the wong place?

--
?? 100% natural

ble

.

WHy do anything when it's so convenient to pay someone to do it for you? I pay a guy to have sex with my girlfriend because I can't be bothered.

Good Luck,

Simon

ery close to 9V

Maybe, but if Vgs

ery close to 9V

No, there is nothing wrong. I wish I could direct you to the specs of IRF9510.

Please try:

ed

very close to 9V

of

e quoted text -

As for the pnp transistor I don't know if it's a bjt or not; can't find the specs. But most (normal) pnp bjt's will do.

ed

very close to 9V

of

e quoted text -

May be I should put a resistor in series with existing resitor and capacitor (that are in parallel) to avoid to much current in the collector of the small transistor. This may be the only flaw. But I think most electrolytics have some resistance (not sure how much this one has)

aced

ng very close to 9V

he

s of

e quoted text -

It (capacitor) doesn't have enogh series resistance (in the vicinity of 1 ohm). So you WERE right. Circuit requies ("small") series resisatance (resistor) in the Emitter. It does work, but I don't know how much longer. Thanks Again. I will modify and repost.

able

re.

" Maybe I should get a Chinaman to mass produce it, market it, and distribute to my "local" handyman store so that you could spend $10 or $20 to buy it.

d

nd

be able

tore.

And just for the record I have nothing against the Chinese or capatilism but why do you even bother to visit? For that matter why do I?

ced

and

er

d be able

store.

e

Don't worry, you're just the straw that broke the camel's back. One day I will learn that this all a waste of time.

Now you're just trolling.

'Bye.

MPM? 'Mighty Proud Moron'?

--
It's easy to think outside the box, when you have a cutting torch.