I need to build a surge suppressor to go on the input of an alarm
circuit. The circuit operates at 24.0 VDC. This is a two wire input
with an end of line resistor. I pulled an AC line toroid off an old
RCA TV and plan to connect it in series with my alarm circuit. Across
the other side of the toroid I plan to connect two 33.0 V MOV's in
series, with the center of the two connected to chassis, (building)
ground. This combination on the other side of the toroid will then be
connected to the alarm input. Additionally across the alarm input will
also be connected a 1.0 uf capacitor. My theory is: a transient first
sees the inductor which by nature resists a change in voltage. Next
come the series MOV's which should direct everything above 24.0 V
between each side of the line and ground, to ground. And finally will
be the cap which will hopefully take care of whatever is left. I know
that there are commercially available filters on the market but I
would really appreciate any thoughts on my idea. Thanks, Lenny

----uuuuuu----,________________
| l
M l
Line |,,,,, __l__ To alarm panel input
in | | ____
M GND l
| l
-----uuuuuu----'_________l,______

On Jul 8, 4:09*pm, "
wrote:
I need to build a surge suppressor to go on the input of an alarm
circuit. The circuit operates at 24.0 VDC. This is a two wire input
with an end of line resistor. I pulled an AC line toroid off an old
RCA TV and plan to connect it in series with my alarm circuit. Across
the other side of the toroid I plan to connect two 33.0 V MOV's in
series, with the center of the two connected to chassis, (building)
ground. This combination on the other side of the toroid will then be
connected to the alarm input. Additionally across the alarm input will
also be connected a 1.0 uf capacitor. My theory is: a transient first
sees the inductor which by nature resists a change in voltage. Next
come the series MOV's which should direct everything above 24.0 V
between each side of the line and ground, to ground. And finally will
be the cap which will hopefully take care of whatever is left. I know
that there are commercially available filters on the market but I
would really appreciate any thoughts on my idea. Thanks, Lenny

* * ----uuuuuu----,________________
* * * * * * * * * * * *| * * * * * * * *l
* * * * * * * * * * * M * * * * * * * l
Line * * * * * * * * |,,,,, * * * *__l__ * To alarm panel input
in * * * * * * * * * * | * *| * * * *____
* * * * * * * * * * * M * *GND * *l
* * * * * * * * * * * *| * * * * * * * *l
* * -----uuuuuu----'_________l,______

The input is aimply a DC voltage of about 15 volts. This is a 24 volt
power limited circuit which has a supervision resistor at the end of
the line. If the line opens the voltage will approach 24 volts and the
system will see a fault but not an alarm. If the line is shorted or
brought very close to zero volts the system will indicate an alarm. A
fuse would seem to make sense but it is not permitted. It sounds crazy
but there must be repeatability so circuit integrity cannot be
compromised by an open fuse. By the same token on opto isolator cannot
be used either because it circumvents the direct connection between
the alarm initiating devices and the input to the panel. It makes for
a frustrating endeavor trying to deal with the realities of the
situation while staying within the guidelines of the original design.
Lenny.

On Tue, 8 Jul 2008 13:09:00 -0700 (PDT),
" put
finger to keyboard and composed:

----uuuuuu----,________________
| l
M l
Line |,,,,, __l__ To alarm panel input
in | | ____
M GND l
| l
-----uuuuuu----'_________l,______

Your ASCII art is barely understandable. You need to use a fixed width
font.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

Franc Zabkar wrote:
On Tue, 8 Jul 2008 13:09:00 -0700 (PDT),
" put
finger to keyboard and composed:

----uuuuuu----,________________
| l
M l
Line |,,,,, __l__ To alarm panel input
in | | ____
M GND l
| l
-----uuuuuu----'_________l,______

Your ASCII art is barely understandable. You need to use a fixed width
font.

- Franc Zabkar

It's readable if you think back to the 'ladder logic' days. I can read
it fine uuu = inductor, M = caps, (unless it means "surgistor").
There's only so much you can do on an ASCII terminal.
Bill Baka

On Jul 12, 12:12*pm, Bill wrote:
Franc Zabkar wrote:
On Tue, 8 Jul 2008 13:09:00 -0700 (PDT),
" put
finger to keyboard and composed:

* *----uuuuuu----,________________
* * * * * * * * * * * | * * * * * * * *l
* * * * * * * * * * *M * * * * * * * l
Line * * * * * * * * |,,,,, * * * *__l__ * To alarm panel input
in * * * * * * * * * * | * *| * * * *____
* * * * * * * * * * *M * *GND * *l
* * * * * * * * * * * | * * * * * * * *l
* *-----uuuuuu----'_________l,______

Your ASCII art is barely understandable. You need to use a fixed width
font.

- Franc Zabkar

It's readable if you think back to the 'ladder logic' days. *I can read
it fine uuu = inductor, M = caps, (unless it means "surgistor").
There's only so much you can do on an ASCII terminal.
Bill Baka- Hide quoted text -

- Show quoted text -

The M's are MOV's the uuuu's are inductors and the cap is to the
right.Lenny

On Sat, 12 Jul 2008 09:12:54 -0700, Bill put
finger to keyboard and composed:

Franc Zabkar wrote:
On Tue, 8 Jul 2008 13:09:00 -0700 (PDT),
" put
finger to keyboard and composed:

----uuuuuu----,________________
| l
M l
Line |,,,,, __l__ To alarm panel input
in | | ____
M GND l
| l
-----uuuuuu----'_________l,______

Your ASCII art is barely understandable. You need to use a fixed width
font.

- Franc Zabkar

It's readable if you think back to the 'ladder logic' days. I can read
it fine uuu = inductor, M = caps, (unless it means "surgistor").
There's only so much you can do on an ASCII terminal.
Bill Baka

I don't have a problem with the OP's choice of letters and symbols.
The problem is that the characters don't appear in their intended
columns. To see what I mean, paste this message text into your word
processor and select a fixed pitch font such as Courier New. Then
change the font to a variable pitch type. I find that Tahoma (Western)
or Britannica Bold give me the best rendering of the OP's drawing.

Now select a variable pitch font, start a new line, and type ten
spaces followed by a period. Then start a new line and type ten 8s,
followed by a new line and ten underscores, new line, and ten dashes,
etc. Now do the same for a fixed pitch font.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

Franc Zabkar wrote:
On Sat, 12 Jul 2008 09:12:54 -0700, Bill put
finger to keyboard and composed:

Franc Zabkar wrote:
On Tue, 8 Jul 2008 13:09:00 -0700 (PDT),
" put
finger to keyboard and composed:

----uuuuuu----,________________
| l
M l
Line |,,,,, __l__ To alarm panel input
in | | ____
M GND l
| l
-----uuuuuu----'_________l,______
Your ASCII art is barely understandable. You need to use a fixed width
font.

- Franc Zabkar
It's readable if you think back to the 'ladder logic' days. I can read
it fine uuu = inductor, M = caps, (unless it means "surgistor").
There's only so much you can do on an ASCII terminal.
Bill Baka

I don't have a problem with the OP's choice of letters and symbols.
The problem is that the characters don't appear in their intended
columns. To see what I mean, paste this message text into your word
processor and select a fixed pitch font such as Courier New. Then
change the font to a variable pitch type. I find that Tahoma (Western)
or Britannica Bold give me the best rendering of the OP's drawing.

That's one of today's problems, started my M$ and their zillion fonts
for windows.

Now select a variable pitch font, start a new line, and type ten
spaces followed by a period. Then start a new line and type ten 8s,
followed by a new line and ten underscores, new line, and ten dashes,
etc. Now do the same for a fixed pitch font.

- Franc Zabkar

Oh Franc,
Let him have some fun. At least he isn't that Curtis Brown jerk/troll.
Bill Baka

"Bill" wrote in message
...
Franc Zabkar wrote:
On Sat, 12 Jul 2008 09:12:54 -0700, Bill put
finger to keyboard and composed:

Franc Zabkar wrote:
On Tue, 8 Jul 2008 13:09:00 -0700 (PDT),
" put
finger to keyboard and composed:

----uuuuuu----,________________
| l
M l
Line |,,,,, __l__ To alarm panel input
in | | ____
M GND l
| l
-----uuuuuu----'_________l,______
Your ASCII art is barely understandable. You need to use a fixed width
font.

- Franc Zabkar
It's readable if you think back to the 'ladder logic' days. I can read
it fine uuu = inductor, M = caps, (unless it means "surgistor").
There's only so much you can do on an ASCII terminal.
Bill Baka

I don't have a problem with the OP's choice of letters and symbols.
The problem is that the characters don't appear in their intended
columns. To see what I mean, paste this message text into your word
processor and select a fixed pitch font such as Courier New. Then
change the font to a variable pitch type. I find that Tahoma (Western)
or Britannica Bold give me the best rendering of the OP's drawing.

That's one of today's problems, started my M$ and their zillion fonts for
windows.

Now select a variable pitch font, start a new line, and type ten
spaces followed by a period. Then start a new line and type ten 8s,
followed by a new line and ten underscores, new line, and ten dashes,
etc. Now do the same for a fixed pitch font.

- Franc Zabkar

Oh Franc,
Let him have some fun. At least he isn't that Curtis Brown jerk/troll.
Bill Baka

He ain't going to have some fun until you go over there and jerk him off and
lick up his cum you jerk/troll.