Camping projector power supply help needed.

Thread Starter

Razzle308

Joined Mar 17, 2016
49
Hi.
A little while ago I bought a 12v projector to take camping. I am having trouble running off battery.
The projector is 12v DC. It has a plug pack that outputs 12v DC @ 5A.
(Simplebeamer C80)
https://www.aliexpress.com/i/32955491257.html

Here goes a long story....
When I ran the projector camping it would play for a time and then shut off. When you try to turn it back on it just flashes and stops. (clue1)
So I thought maybe it was getting hot.
So when I came home I did some testing and in the process accidentally mixed the power supply up with a 2Amp supply.
So when I tested it, it did the same. Ran for about 10mins and stopped, flashes when you try to turn it back on.
After going back n forth with the seller I realised the power supply mix-up, connected the 5A supply and it works fine.(clue2)
So now I'm thinking that the issue is voltage/current draw.

So given that I am running off a battery and at the end of a cable run I bought a voltage boost module (6amp).
So at the end of the projector cable I do have 12.4v. I can boost that up to 17v if needed. But the projector still won't run. just flashes.
(qsjk 6A boost module)
https://core-electronics.com.au/150...an0qX4gZ631oefU6xY8eEjZ5grZeAaZBoCXDkQAvD_BwE

Any ideas what my issue is?
I don't really understand why the projector won't run at the end of the cable if the voltage reads ok there. It a 4mm twin cable so it can deliver the current.

Just to confirm. The projector will run on the cable even momentarily so there is not connection or wiring issues.

Thanks, Darren.
 

SamR

Joined Mar 19, 2019
3,391
I think you are right. That projector's bulb eats up some power. Surprised it even has a 12VDC port. Not sure what kind of camping but that thing is going to need a substantial battery. Does it have any paperwork with specifications, which is usually scarce for AliX products.
 

Thread Starter

Razzle308

Joined Mar 17, 2016
49
I think you are right. That projector's bulb eats up some power. Surprised it even has a 12VDC port. Not sure what kind of camping but that thing is going to need a substantial battery. Does it have any paperwork with specifications, which is usually scarce for AliX products.
Hi.
It is an LED projector. 60watts
We have a 120AH deep cycle battery.
There are no "specs" on the projector. Just the power supply spec.
 

SamR

Joined Mar 19, 2019
3,391
K, then the load should be less for the LED bulb. Without specs, you are just guessing. IF you know how you would need to measure the 12V amperage. From the 60W figure, 60W/12V=5A and that is for the bulb alone and not the total draw. So you should, for the 120AH battery get ~4 hours. Not sure what you are using for a cable but it should handle the ampacity so maybe 6A which would be ~18AWG wire minimum. What can happen is the load requires a fixed amount of power and if it isn't getting enough current it starts dropping in voltage and things quit working.
 

Thread Starter

Razzle308

Joined Mar 17, 2016
49
K, then the load should be less for the LED bulb. Without specs, you are just guessing. IF you know how you would need to measure the 12V amperage. From the 60W figure, 60W/12V=5A and that is for the bulb alone and not the total draw. So you should, for the 120AH battery get ~4 hours. Not sure what you are using for a cable but it should handle the ampacity so maybe 6A which would be ~18AWG wire minimum. What can happen is the load requires a fixed amount of power and if it isn't getting enough current it starts dropping in voltage and things quit working.
So 4mm cable is rated to 28amps. The reason I bought the module was to ensure any losses (to a point) would be ironed out at the projector end by the module.
So is the module not doing what is should or am I still not understanding something?
 

DickCappels

Joined Aug 21, 2008
7,418
If you know the minimum input voltage for the projector, measure the voltage at the end of the cable while the projector is projecting. That should tell you something about the battery, the cable, the connectors or the projector.

Knowing the voltage drops you can narrow down the choice of problems, but take the measurements under load.
 

Thread Starter

Razzle308

Joined Mar 17, 2016
49
If you know the minimum input voltage for the projector, measure the voltage at the end of the cable while the projector is projecting. That should tell you something about the battery, the cable, the connectors or the projector.

Knowing the voltage drops you can narrow down the choice of problems, but take the measurements under load.
Ok. So the voltage drop when the projector starts up is from 12.4v to 8.8v
When I put the module in i am reading 12.4 volts on the output and the projector just flashes. There is not even time for the multimeter to register a drop.
 

Thread Starter

Razzle308

Joined Mar 17, 2016
49
According to the specifications for the input power, can the projector work at 8.8 Vin?
well, like i say there are no specs but given it is 12v I don't imagine it would be happy about 8,8v
It starts and boots - but will shortly shut off.
But the point of the boost module is to maintain 12v despite loss over the cable. yes?
 

DickCappels

Joined Aug 21, 2008
7,418
But the point of the boost module is to maintain 12v despite loss over the cable. yes?
I don't know about your boost module, but if its purpose is to compensate for voltage drop, it is not being very successful at it.
How long is your cable?
Do you know the resistance of your cables + connector (round trip)?
Is the boost module rated for the full 5 amps?
 

Thread Starter

Razzle308

Joined Mar 17, 2016
49
I don't know about your boost module, but if its purpose is to compensate for voltage drop, it is not being very successful at it.
How long is your cable?
Do you know the resistance of your cables + connector (round trip)?
Is the boost module rated for the full 5 amps?
I mentioned he boost module in the op.
 

DickCappels

Joined Aug 21, 2008
7,418
Yes, I remember, but what is the voltage drop along your cable? Seems like about 4 volts. What is the total resistance of your connectors and cable?
 
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