Another electric question

[Jeff2010]

I’ve got a BlueSea fuse block connected to an AC-DC converter that I’m using to mimick a final battery connection. I want to connect four circuits to it and the three that power some lights work just fine. The total draw for those are 9.7 watts. When I add the fourth circuit which is to a 12v tv (draws 17 watts) it doesn’t even turn on. I’m guessing it’s because the wattage combination is too much for the converter. If I’m sending 24v to the block…why is this happening and what’s the best way to resolve it? My plan was to push 24v from the batteries to a 24-12 step down then into the block…what am I missing?

Thanks!!

 

[AlphaHare]

One idea - some (most) inexpensive AC-DC inverters make a very choppy 'modified' sine wave that will not work with many electronics. Check your specs - pure sinewave, or modified sinewave?

 

[Jeff2010]

I just checked online…got this back:

No, the Hanmatek HM310 is a DC power supply, not an AC inverter, so the concept of “pure sine wave” doesn’t apply in the same way it does for AC output devices.

The HM310 is a regulated DC bench power supply designed to provide adjustable DC voltage and current (up to 30V and 10A). It outputs DC power, not AC, so it does not generate any kind of sine wave—pure or modified.

 

[PorchDog]

If your TV is 12 volts-- why are you sending 24 volts to the Fuse Block? Maybe the lights could tolerate the 24 volts-- but the 12 volt TV can't tolerate the 24 volts, and appears as a short circuit-- or you fried the TV?

I just didn't understand about sending 24 volts TO the fuse block-- if your intentions are to power 12VDC devices?

 

[Jeff2010]

Reply

If your TV is 12 volts-- why are you sending 24 volts to the Fuse Block? Maybe the lights could tolerate the 24 volts-- but the 12 volt TV can't tolerate the 24 volts, and appears as a short circuit-- or you fried the TV?

I just didn't understand about sending 24 volts TO the fuse block-- if your intentions are to power 12VDC devices?

Before I did the fuse block I had the circuit on a long run and I found the tv needed 19volts to operate. I attributed it to voltage drop and I’m going to be sending 24volts and step it down to 12volts before it goes to the fuse block.

In retrospect, the voltage drop wasn’t an issue as the tv is still requiring 19v to start…and the TV works by when it’s by itself on the fuse block…

 

[PorchDog]

At these very low power levels, I do not understand how you could be having these types of voltage drops with even 18 gauge wire. The nominal 12 volt stuff will be around 13.00 volts when attached to a battery, and I would think even a 1 volt drop on a normal run would be normal. Not several volts. The fact that the fuse block will work the TV by itself, or the lights by themselves points to a voltage drop problem somewhere. Wire size, connection quality, or something...

My 3 cents.

 

[Jeff2010]

Ok…I’m an idiot

There isn’t an issue…my power supply I’m using apparently defaults to constant current…I was reacting and didn’t realize it was trying to help
Setting it to be constant voltage works just fine…what a senseless waste of time

 

[PorchDog]

Learn something every day.

 

[Rucker]

There isn’t an issue…my power supply I’m using apparently defaults to constant current…I was reacting and didn’t realize it was trying to help
Setting it to be constant voltage works just fine…what a senseless waste of time

Happens to the best of us.

 

[nikitis]

Fun fact I learned was that power from the power company in many areas isn't considered clean power.

"Clean" in this instance is usually referred to as a constant power. Unclean would mean inconsistent power as in it fluctuates. 15 to 20 years ago it was more of a requirement to send clean power to houses, but as the grid has grown and the nation attempting to maintain a 60hz frequency across the whole network is proving more and more difficult there's been slack in the clean power sent to homes. Power supplies over the last 15 years have adjusted their electronics to have more capacitors built into them to turn unclean power into clean power for the devices the power supply is requiring.

Capacitors job is to store power from an unclean source and deliver it clean and constant to the device. So if capacitors start to go bad it can cause issues or pop and not work at all because the line was disconnected.

Now turn to a bus application. Solar is DC current, but panels themselves fluctuate based on amount and intensity of sunlight they receive. Battery banks in our case act as Capacitors as well in our system. They store power from unclean source such as the panels and delivers clean direct power to your devices.