Converting AC - DC Help

dl324

Joined Mar 30, 2015
18,328
He meant - can you use the signal that turns on the sounders to turn on the siren?

I'd add some surveillance cameras too...
 

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G4M8L3R08

Joined Dec 27, 2014
32
He meant - can you use the signal that turns on the sounders to turn on the siren?

I'd add some surveillance cameras too...
I have 6 cameras up in total on the property however the person who was snooping came prepared and hooded up, the floodlights help provide what he was wearing but the police said it could be anybody so in the mean time ill just keep the chainsaw handy....
 

gerty

Joined Aug 30, 2007
1,305
I am not familiar with the term "sounders" so I don't know their workings, but if you want this relay to stay on (latch) and the sounders are momentary you'll have to provide some sort of latch/reset..
 

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G4M8L3R08

Joined Dec 27, 2014
32
I'd be out there with a shotgun...
Unfortunately I only have a c02 rifle and pistol, then again could just put our lasses picture on the front door.......
I am not familiar with the term "sounders" so I don't know their workings, but if you want this relay to stay on (latch) and the sounders are momentary you'll have to provide some sort of latch/reset..
As long as the sounder is live and showing the 60vac then my siren 12v circuit needs to remain working, once the sounder stops and the 60vac drops then my circuit needs to open
 

dl324

Joined Mar 30, 2015
18,328
Unfortunately I only have a c02 rifle and pistol
Hopefully your law enforcement can get there quickly when needed. In my area, might get some help in 45 minutes; people in my neighborhood have to be more self sufficient out of necessity...
 

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G4M8L3R08

Joined Dec 27, 2014
32
Hopefully your law enforcement can get there quickly when needed. In my area, might get some help in 45 minutes; people in my neighborhood have to be more self sufficient out of necessity...
Took them just under 1 hour to arrive, I was told that it wasnt priority as the person had left the scene and didnt break an entry.......so my next move is pretty clear, invite him in first and then phone the police...
 

ian field

Joined Oct 27, 2012
6,536
Took them just under 1 hour to arrive, I was told that it wasnt priority as the person had left the scene and didnt break an entry.......so my next move is pretty clear, invite him in first and then phone the police...
Seems about the same pretty much anywhere - most coppers couldn't catch a cold!
 

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G4M8L3R08

Joined Dec 27, 2014
32
Evening all, I put a circuit together about half an hour ago.
I managed to get the voltage at point A down to 1.4v however when I connect the opto coupler the voltage reduces to .7v...... obviously this isnt enough to close the circuit on the other side as planned.
Any ideas?
 

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ian field

Joined Oct 27, 2012
6,536
Evening all, I put a circuit together about half an hour ago.
I managed to get the voltage at point A down to 1.4v however when I connect the opto coupler the voltage reduces to .7v...... obviously this isnt enough to close the circuit on the other side as planned.
Any ideas?
The voltage divider is probably more than you need for driving an opto-coupler LED.

I'd go for a simple series current limiting resistor - with the large available voltage headroom you have, its probably safe to ignore a voltage as small as the Vf of the opto LED.

Look on the opto coupler data sheet and find out what current the LED needs to make the output transistor conduct.

Someone else estimated that your peak rectified and smoothed voltage will be about 80V, it wouldn't hurt to actually measure it and see. Use Ohm's law to calculate the resistor value to limit the current to the required value - don't forget to calculate what power the resistor will dissipate.
 

MaxHeadRoom

Joined Jul 18, 2013
30,661
Evening all, I put a circuit together about half an hour ago.
I managed to get the voltage at point A down to 1.4v however when I connect the opto coupler the voltage reduces to .7v...... obviously this isnt enough to close the circuit on the other side as planned.
Any ideas?
With no cap as shown, the DC will be <60vdc.
The one in #23 works, I tried it;)
Max.
 
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