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Author Topic: Calling doorbell  (Read 7005 times)

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cheerio

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Re: Calling doorbell
« Reply #15 on: April 05, 2012, 22:26:03 PM »
i am using a switch mode psu. 230vAC -> 5vDC
The ringing signal is 12vAC and completely decoupled by a relay. If the relay is activated it connects the 5vDC of my circuit to a pin on the MCU.

i will buy another switch mode PSU which might solve the problem. 5€ is worth a shot

George

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Re: Calling doorbell
« Reply #16 on: April 06, 2012, 01:42:08 AM »
Another method is to put a transorb diode on the DC input to filter out the spikes
« Last Edit: April 06, 2012, 05:10:29 AM by George »

kam

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Re: Calling doorbell
« Reply #17 on: April 06, 2012, 07:46:30 AM »
i will buy another switch mode PSU which might solve the problem. 5€ is worth a shot

or you might try a linear supply with transformer?

cheerio

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Re: Calling doorbell
« Reply #18 on: April 06, 2012, 14:04:14 PM »
this would be too big. the casing is pretty flat

kam

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Re: Calling doorbell
« Reply #19 on: April 06, 2012, 15:54:33 PM »
this would be too big. the casing is pretty flat

so you use a flyback SMPS from 220 directly to supply right?

cheerio

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Re: Calling doorbell
« Reply #20 on: April 06, 2012, 16:52:46 PM »
i use a 9V smps, a 5v fixed voltage reg. and some caps to ensure a stable voltage. The new smps would deliver 5V DC / 2A out of the box.

kam

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Re: Calling doorbell
« Reply #21 on: April 06, 2012, 17:16:48 PM »
i use a 9V smps, a 5v fixed voltage reg. and some caps to ensure a stable voltage. The new smps would deliver 5V DC / 2A out of the box.

but the smps gets power directly from 220V?

cheerio

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Re: Calling doorbell
« Reply #22 on: April 06, 2012, 20:08:13 PM »
yes

kam

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Re: Calling doorbell
« Reply #23 on: April 07, 2012, 14:13:33 PM »
so it is probably a flyback SMPS. is it possible that you do a test with a PC supply?

cheerio

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Re: Calling doorbell
« Reply #24 on: April 07, 2012, 18:30:12 PM »
All the PC PSU i own have Voltage spike filters, so it would solve the issue. But they are too big ^^
If the new PSU does not fix the problem i will salvage a filter from an old PC PSU.

kam

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Re: Calling doorbell
« Reply #25 on: April 08, 2012, 13:26:20 PM »
That is what i wanted to confirm. most probably a voltage suppressor and some sort f filtering at the input will work pretty well for you.