Audiovox AVT-1498 Operations Instructions download pdf (Page 33)

–26–

Amperage

A TV will draw considerably more amperage than a VCP. For instance, a 9” TV will draw

approximately 3.0 amps compared to a VCP that draws 1 amp while the tapes are 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 .5 VDC (11 VDC) less than the TV.

In conclusion, operating these video products without the engine running will drain the battery to

the point where these products will perform unacceptably in a short period of time.

Converters

Many RV OEM's incorporate converters as a source of 12 VDC when connected to shore power

(110-120 VAC). Some models put out a very clean DC supply where others may have a

considerable amount of AC ripple under maximum load.

This AC ripple is filtered by the coach battery when connected into the circuit, but when the battery is

removed or disconnected the amount of AC ripple can create major problems for audio and video

products. Noise may result and often times in line fuses fail.

Ignition Systems

Unwanted noise generated from ignition systems used to be a big problem. However, with more

sophisticated filtering circuits designated into audio/video products, these problems are not as

wide spread.

Changes in wire harnessing also has contributed to the decline of application problems. One rule of

thumb is to use the same ground point for all related products. This will greatly reduce the potential

for alternator whine.

1 2 ... 28 29 30 31 32 33 34 35 36 37 38 39

No comments

Audiovox AVT-1498 Operations Instructions Page 33