YOU BUILD-IT SURGE PROTECTORS

Surge protectors are not really that mysterious and are easily constucted at
home. There are many ways to protect a line from power surges, but the style
that I'll deal with here is the quickest acting form available (also the least
expensive). This form won't protect your system however from direct lightening
stikes, but can be used in conjunction with the heavier (slower) type that is
capable of handling that type of load (eg. a direct lightening strike to
your house line).

Metal-Oxide Varistors (MOV for short) can absorb the excess (or high surge)
voltages above the starting point designed for the particular MOV (130v for
most of our applications) up to about 50,000 volts (again depending upon
design. this information is available from the mfg's spec. sheets).

A MOV is a variable resistor that does nothing until line voltage (where
it's attached) exceeds it's specified threshold. At this time, the MOV then
absorbs any voltage greater than the starting point for that particular MOV.
(the voltage differences are detected between the two lines on your system)
Enough of this quasi-technical stuff. I'll just get into how to build your
own surge protectors.

There are several designs for using MOVs. The one that works best will be
described here. This design allows for total benefit of the MOVs. For each
surge protector you wish to construct, you'll need three (3) MOVs. You'll
also need some type of multiple outlet device that has enough room inside of
it to allow installation of these three MOVs. And you'll also need to be able
to solder these electronic devices (it's really not that difficult).

Each MOV has two (2) leads extending from it and are soldered to two of the
three AC powerlines inside your multiple outlet.(see diagram)


O __________________________
/ \ [ ]
/ \ [ O = MOV ]
|/ | \| [ ]
| | | [ / or \ = leads ]
| O | | [ ]
|/ \| | [ | = AC lines]
| | O | [__________________________]
| |/ \|
HOT --------------> | | |
NEUTRAL --------------> | |
GROUND -------------------> |

I should explain the reason for using three (3) MOVs. A MOV detects voltage
changes between the two lines (hot & neutral). So, if you only use one MOV,
and both lines get zapped with the same surge of equal voltage, there is no
difference detected between the lines (therfore, IT DON'T WORK!!!). So, if
you use three (3) MOVs, as shown in the diagram, the difference will be
detected.

After soldering, check your work for shorts , reassemble the multiple
outlet, and check AGAIN for shorts.

Before leaving you may be wondering, "How much each MOV will set you back?".
These devices are very inexpensive, generally anywhere from $ 1.50 to $ 5.00 ea.

I would also like to say that due to my inability to control your parts
purchase AND your ability to solder components, I assume NO LIABILITY for the
information contained in this article. I do personally use the construction
as described, but non-the-less!

Chemical Kidd
Houston, Tx.


Parts are available from: ACE Electronics
(these are all in Houston)
Gateway Electronics

Radio Shack

********************************************************************************
One for the Phone (SURGE pt.2)
********************************************************************************
To build a protector for a phone line is basicly the same as building one
for your AC line. The biggest difference is the maximum voltage the MOV
should begin to activate.
eg. AC line voltage is about 120 VAC & the MOV swings in at 130 VAC.
for the phone lines the MOV should swing in about 7-8 VDC.

The diagram for the protection of all 4 wires entering the modem is as follows:


O
O / \
/ \ / \ ___________________________
NO connection here -----> / / \ [ ]
between the two MOVs ( ( \ | [ O = MOV ]
(see below) | | \| | [ ]
| | | | [ / or \ = MOV leads ]
| O | | O | [ ]
|/ \| |/ \| [ | = PHONE lines]
| | O | | [___________________________]
| |/ \| |
RED --------------> | | | |
GREEN ----------------> | | |
YELLOW -------------------> | |
BLACK ------------------------> |

_O_
/ \
/ \
( )
| | | |
to further clarify ---> |-O-|-O-|-O-|
the connections | | | |
( )
\ /
\_ _/
O


Judging from the size of the $19.95 phone surge protectors, the diagram
being used is as follows:
___________________________
[ ]
[ O = MOV ]
| | [ ]
| | [ / or \ = MOV leads ]
| O | [ ]
|/ \| [ | = PHONE lines]
| | [___________________________]
| |
RED --------------> | |
GREEN ----------------> |


As stated in the previous section, this last diagram works fine of only one (1)
line gets the surge. But, if both lines get zapped, you can forget it ever
working. Red and Green wires are your carrier lines but, with today's new rules
on do-it-yourself installations, double-check to be sure.

The case for using five (5) MOVs runs somewhere in the neighborhood of $5-7.
The cases are available from various hardware sources & electronic supply co.

AND, once again due to my inability to control the construction of,choice of
materials,....etc. , etc., etc. I can assume NO responsibility for the previous
information nor its use.
Thank you,
Chemical Kidd
Houston, Tx