TV with 14v brick, okay at 12.x volts?

camperpaul wrote:
Ted,
Without the DC-DC converter, the battery powered device will usually turn itself off when the battery voltage reaches ~11 Volts.

With the dc-dc converter, the device will still be getting 12 Volts when the battery voltage is 9Volts!, well past the permanent damage SOC.

Thanks for the explanation. That makes a good argument for big power users to have a battery monitor.

Ted H.

Ted,
Without the DC-DC converter, the battery powered device will usually turn itself off when the battery voltage reaches ~11 Volts.

With the dc-dc converter, the device will still be getting 12 Volts when the battery voltage is 9Volts!, well past the permanent damage SOC.

camperpaul wrote:

wxtoad wrote:

2oldman wrote:
I wonder if there's a DC-DC "inverter", which would take a range of input DC voltages and crank out a steady 14v.

Check out the Meanwell DC-to-DC converters - you can get them in many different input/output configurations. I have one that has an input of 9-15 volts and puts out a steady 12 volts. I use it to power a few sensitive electronic devices.

Ted H.

The problem with doing it that way is when the battery voltage drops below a critical point, permanent damage is done to the battery.

What does using a dc-to-dc converter have to do with running down the batteries too much? That can happen just as easily without a converter.

Ted H.

camperpaul wrote:

wxtoad wrote:

2oldman wrote:
I wonder if there's a DC-DC "inverter", which would take a range of input DC voltages and crank out a steady 14v.

Check out the Meanwell DC-to-DC converters - you can get them in many different input/output configurations. I have one that has an input of 9-15 volts and puts out a steady 12 volts. I use it to power a few sensitive electronic devices.

Ted H.

The problem with doing it that way is when the battery voltage drops below a critical point, permanent damage is done to the battery.

tie a relay in, that is latched to the battery, most automotive relays drop out at 10/11v which would kill the meanwell

might have to play with resistors on the latch terminal to find a range that works.


cheapest LVC i can think of in 30 seconds

wxtoad wrote:

2oldman wrote:
I wonder if there's a DC-DC "inverter", which would take a range of input DC voltages and crank out a steady 14v.

Check out the Meanwell DC-to-DC converters - you can get them in many different input/output configurations. I have one that has an input of 9-15 volts and puts out a steady 12 volts. I use it to power a few sensitive electronic devices.

Ted H.

The problem with doing it that way is when the battery voltage drops below a critical point, permanent damage is done to the battery.

2oldman wrote:
I wonder if there's a DC-DC "inverter", which would take a range of input DC voltages and crank out a steady 14v.

Check out the Meanwell DC-to-DC converters - you can get them in many different input/output configurations. I have one that has an input of 9-15 volts and puts out a steady 12 volts. I use it to power a few sensitive electronic devices.

Ted H.

wa8yxm wrote:
Gde... I agree with you it is MOST LIKELY a ground loop. but here is my problem.. Easily gotten around.

In my car, I do not have A/V in on the dash like my daughter does and my motor home does.. I do have a cassette deck however and the fake cassett which lets me play my phone through the cassette system..

Now this is transformer coupled, no direct electrical connection (At least I hope. May lay a piece of tape over the head to isloate and try again).

I get the same kind of noise on the cassette magnetic coupled system I get with the direct A/V The noise I asssoicate with ground loups and common mode interference. in this case using the 120 volt adapter I have and an MSW inverter.. No help.

Run it (The phone) on battery (internal) no noise.

The music is beautiful too. Pange Lingua Gloriosi (Got to learn that stuff before Easter)

Correct.

A tape "adapter" like you have is basically a one for one transformer which may or may not be electrically isolated as far a grounds go.

Pretty simple device, nothing more than a tape player head in the device which when inserted loosely "couples" magnetically to the tape head in the player.

The head coils in the player and the adapter are most likely "grounded" to the shield (ground) wires which can complete the ground loop.

Potentially the head coils could be separated from the outside shell of the head depending on the design, doing so would break any ground loop that may happen when the adapter is inserted.

However in practice I never had any real luck using tape adapters, they just never seem to work all that well for me. Had at one time a 8 track one and a few cassette ones (might even have a cassette adapter in a junk box). While they transferred the audio it never sounded that good and often was picky on how well it seated in the player.

But.. Depending on the phone you have your headphone output may or may not have an additional connection for the mic (after all the main reason for a phone is to talk and many hands free headsets include mics).

So, your phone could have mono audio out and mic in (three pin jack OR FOUR PIN jack), stereo out only (three pin jack) or stereo out, mic in (FOUR PIN jack).

Some of those combinations will require the proper adapter to connect a three pin audio plug correctly...

Although if you have a iphone you might have an optional adapter cable which functions as a break out device as to how that is wired I do not know..

Gde... I agree with you it is MOST LIKELY a ground loop. but here is my problem.. Easily gotten around.

In my car, I do not have A/V in on the dash like my daughter does and my motor home does.. I do have a cassette deck however and the fake cassett which lets me play my phone through the cassette system..

Now this is transformer coupled, no direct electrical connection (At least I hope. May lay a piece of tape over the head to isloate and try again).

I get the same kind of noise on the cassette magnetic coupled system I get with the direct A/V The noise I asssoicate with ground loups and common mode interference. in this case using the 120 volt adapter I have and an MSW inverter.. No help.

Run it (The phone) on battery (internal) no noise.

The music is beautiful too. Pange Lingua Gloriosi (Got to learn that stuff before Easter)

garry1p wrote:
While I think the TV will work OK I would buy an inexpensive 50 or 100W converter for the isolation.

OP already has an inverter but like a lot of folks here, they are trying to REDUCE the wasted power lost by the inverter AND the power brick.. Basically by removing double conversion of power they can watch the TV longer or reduce the recharge time.

If they want to continue to use the DVD player and TV without the inverter then using the video and audio ground loop transformers would solve that problem without using any more power..

While I think the TV will work OK I would buy an inexpensive 50 or 100W converter for the isolation.