ASA Electronics MS-306 - Manual (Page 12)

Audiovox Specialized Applications, LLC
T E C H N I C A L B U L L E T I N
This bulletin will discuss DC Power sources and
how they relate to 12 volt DC video products.
DC (Direct Current) Power
A large number of our products are designed for
12 volt DC applications. The power is supplied by
a variety of sources i.e., the battery, converters,
ignition systems and solar power.
General Specifications
Our general specification for the voltage range of
operation is 10 to 16 volts DC. TV’s and VCP’s
(video cassette players) require slightly more than
10 volts to function properly. Normally this 10.5 to
11 voltage requirement does not create a problem,
but keep in mind the following points:
Voltage
The voltage of a fully charged battery (engine not
running) is approximately 12.5 VDC. Once a load
(items being powered represent the “load”) is
applied, the voltage will drop. How much the
voltage is reduced will depend on the following:
1. Current draw (amount of amperage); the
higher the draw the greater the voltage
will drop.
2. This size and length of the conductor
(wire) supplying power.
Amperage
A TV will draw considerably more amperage than
a VCP. For instance, a 14” TV will draw
approximately 3.5 amps compared to a VCP that
draws 1 amp while the tape is being loaded or
ejected. Checking the voltage of a TV while it is
playing shows an approximate 1 volt drop, (11.5
VDC). The voltage at the VCP can be another
.5VDC (11 VDC) less than the TV.