M
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Guest
How to start with the wrong voltage and get it to work?
Sorry for how long the post turned out to be. These first 3 questions
are somewhat academic, so please don't scowl at me.
Questions D and E are the most interesting, and the only ones I really
need solved soon. A and B interest me. I know variation is possible,
but have too little experience to even guess how much.
My friend** almost bought a garage door receiver that was able to run
on 12 or 24 volts AC:
A. Is it likely that one can run a 12 volt AC garage door receiver
off of the existing 16 volt AC adapter with no damage to the receiver?
B. Is it likely that one can run the same AC garage door receiver set
for 24 volts, off of the same 16 volt AC adapter, and it will work?
Will reception probably be a lot weaker?
C. Is it likely the difference between the 12 and 24 volt settings is
just a resistor in series for the 12 volt setting, and I could replace
that with a lower ohm resistor so it would run fine on 16 volts??
D-setup. We may be able to change the transformer to 24vac. This is
a garage door receiver with no garage door. The receiver is inside
the house on a closet shelf near the front wall (1960's house, brick)
and includes relay A in it which controls another relay B in the
basement which controls a rated 24-volt latching relay C that turns on
floodlights outside the house. They use them when they come home,
especially the wife who's a bit scared and also doesn't walk well.
D-question. So, if relay B's coil was set up to run on, has been
running on 16 volts AC, is there any chance changing it to 24 volts AC
could cause a problem? The relay is only closed for 2 to 5 (10 maybe,
if someone is berserk) seconds once or twice a day when someone in a
car pushes the button on the remote.
E-setup. It turns out that he found at Radio Shack a unit, with only
one remote, for only 3 dollars! Closeout. What luck. First store he
went to. It runs on 12 volts, AC. His electronics friend at work
tells him about a voltage divider, but my objection is that will mean
the AC transformer is providing output current ALL the time.
E-question. I would rather start with a high value resistor in series
between the 24 volts and the 12 volt device, lowering the value^^
until there is 12 or 13 volts across the device. Seems to me, this
receiver always uses the same current, except maybe when closing its
relay, but that shouldn't draw enough more to lower the voltage enough
to cause a problem. If testing shows it does lower the voltage, then
I would consider setting the usual voltage at 13. Is my way likely
to work? and assuming it works, woudln't it be better? Not waste
electricity?
^^This would also give me a chance to use my resistor box that I got
at a flea market and have only used once.
**For some reason after my friend bought this house he went around the
house removing anything he didn't like, including the receiver for
this light setup, and then he threw it away.*** He also
disconnected the alarm tape on the windows saying that tape was
obsolete, even though he didn't replace it with anything, or even
remove the rest of the tape!! I'm seeing a whole new side of this
guy.
Normally I'd do almost any amount of work for my friend -- he also
does a lot for me -- but I don't feel like putting in more effort than
necessary to overcome his stupidity!
***The transmitters, 10 or 20 or 25 years old, are still sold, but we
can't find a receiver that works with the transmitters. New ones are
310 megahertz and these are 303.xxx megahertz. New receiver sets are
as low as 60 dollars, or 32 on ebay for some left-over Viper car alarm
fobs that they matched up with a garage door opener receiver. Good
for them, not wasting the stuff.
Frankly the whole thing seems like a good idea, for a lot of people
who are afraid to come home in the dark, or need the light not to
trip.
F. I presume the relay is there because the installer, maybe the
burglar alarm installer, thought that the garage door receiver
mechanical relay couldn't handle the current for the 24 volt latching
relay C. Does that sound right?? Now that the relay is there, in its
own metal box, I see no reason to eliminate it. but do you think the
installer was likely to be right? I ask because for my car alarm,
I was afraid to power the door lock solenoids, two of them, pretty
big, from the mechanical relay in the alarm box, and the instructions
weren't perfectly clear, so I put another relay in between.
Thanks a lot for any help.
Sorry for how long the post turned out to be. These first 3 questions
are somewhat academic, so please don't scowl at me.
Questions D and E are the most interesting, and the only ones I really
need solved soon. A and B interest me. I know variation is possible,
but have too little experience to even guess how much.
My friend** almost bought a garage door receiver that was able to run
on 12 or 24 volts AC:
A. Is it likely that one can run a 12 volt AC garage door receiver
off of the existing 16 volt AC adapter with no damage to the receiver?
B. Is it likely that one can run the same AC garage door receiver set
for 24 volts, off of the same 16 volt AC adapter, and it will work?
Will reception probably be a lot weaker?
C. Is it likely the difference between the 12 and 24 volt settings is
just a resistor in series for the 12 volt setting, and I could replace
that with a lower ohm resistor so it would run fine on 16 volts??
D-setup. We may be able to change the transformer to 24vac. This is
a garage door receiver with no garage door. The receiver is inside
the house on a closet shelf near the front wall (1960's house, brick)
and includes relay A in it which controls another relay B in the
basement which controls a rated 24-volt latching relay C that turns on
floodlights outside the house. They use them when they come home,
especially the wife who's a bit scared and also doesn't walk well.
D-question. So, if relay B's coil was set up to run on, has been
running on 16 volts AC, is there any chance changing it to 24 volts AC
could cause a problem? The relay is only closed for 2 to 5 (10 maybe,
if someone is berserk) seconds once or twice a day when someone in a
car pushes the button on the remote.
E-setup. It turns out that he found at Radio Shack a unit, with only
one remote, for only 3 dollars! Closeout. What luck. First store he
went to. It runs on 12 volts, AC. His electronics friend at work
tells him about a voltage divider, but my objection is that will mean
the AC transformer is providing output current ALL the time.
E-question. I would rather start with a high value resistor in series
between the 24 volts and the 12 volt device, lowering the value^^
until there is 12 or 13 volts across the device. Seems to me, this
receiver always uses the same current, except maybe when closing its
relay, but that shouldn't draw enough more to lower the voltage enough
to cause a problem. If testing shows it does lower the voltage, then
I would consider setting the usual voltage at 13. Is my way likely
to work? and assuming it works, woudln't it be better? Not waste
electricity?
^^This would also give me a chance to use my resistor box that I got
at a flea market and have only used once.
**For some reason after my friend bought this house he went around the
house removing anything he didn't like, including the receiver for
this light setup, and then he threw it away.*** He also
disconnected the alarm tape on the windows saying that tape was
obsolete, even though he didn't replace it with anything, or even
remove the rest of the tape!! I'm seeing a whole new side of this
guy.
Normally I'd do almost any amount of work for my friend -- he also
does a lot for me -- but I don't feel like putting in more effort than
necessary to overcome his stupidity!
***The transmitters, 10 or 20 or 25 years old, are still sold, but we
can't find a receiver that works with the transmitters. New ones are
310 megahertz and these are 303.xxx megahertz. New receiver sets are
as low as 60 dollars, or 32 on ebay for some left-over Viper car alarm
fobs that they matched up with a garage door opener receiver. Good
for them, not wasting the stuff.
Frankly the whole thing seems like a good idea, for a lot of people
who are afraid to come home in the dark, or need the light not to
trip.
F. I presume the relay is there because the installer, maybe the
burglar alarm installer, thought that the garage door receiver
mechanical relay couldn't handle the current for the 24 volt latching
relay C. Does that sound right?? Now that the relay is there, in its
own metal box, I see no reason to eliminate it. but do you think the
installer was likely to be right? I ask because for my car alarm,
I was afraid to power the door lock solenoids, two of them, pretty
big, from the mechanical relay in the alarm box, and the instructions
weren't perfectly clear, so I put another relay in between.
Thanks a lot for any help.