12 Volt DC Connected to 120 Volt AC

  • Thread starter Thread starter John1397
  • Start date Start date
  • Tags Tags
    Ac Dc Volt
AI Thread Summary
Connecting 12 volts DC to 120 volts AC through a diode can cause significant issues, as the AC voltage may drop below 12 volts and reverse polarity, potentially drawing current from the battery. This scenario could lead to excessive current flow, risking battery damage, wire melting, or even explosion. The discussion emphasizes the dangers of handling mains voltage and large batteries without proper knowledge. A suggested solution involves using a switch and two relays to manage the voltage safely. Overall, the thread highlights the critical safety concerns associated with this electrical setup.
John1397
Messages
189
Reaction score
18
12 volts DC will travel thru a Diode connected to 120 volt AC , but will it put any load on the battery?

John
 

Attachments

  • 12volt To 120 Volt.jpg
    12volt To 120 Volt.jpg
    9.7 KB · Views: 631
Engineering news on Phys.org
Well, when the AC voltage drops below 12v and then goes into the negative part of its cycle, it will pull current out of the battery, theoretically an infinite amount assuming ideal sources, thereby causing the battery to explode. Don't try this at home, kids !
 
This is not a good idea. During the negative cycle of the AC (the + and- are reversed) and current will flow from the + of the battery through the diode- in fact, as soon as the AC terminal voltage drops below +11.4 volts or so and the current will eventually be so high that it will knacker the battery, melt the wires , blow a fuse.
Don't touch mains voltages or big batteries until you can answer this sort of question yourself, without asking anyone. Be safe.
 
One switch and two relays should work as the yellow line should carry 12 volts when power is off and carry 120 volts when switch on?

John
 

Attachments

  • 12 volt To 120 Volt.jpg
    12 volt To 120 Volt.jpg
    19.9 KB · Views: 601
John1397 said:
12 volts DC will travel thru a Diode connected to 120 volt AC , but will it put any load on the battery?

John

John1397 said:
One switch and two relays should work as the yellow line should carry 12 volts when power is off and carry 120 volts when switch on?

John

Wow, crazy dangerous. Thread is closed.
 
  • Like
Likes 1 person

Thread 'Underwater piezoelectric sensor array receive sensitivity'

Hi all I have some confusion about piezoelectrical sensors combination. If i have three acoustic piezoelectrical sensors (with same receive sensitivity in dB ref V/1uPa) placed at specific distance, these sensors receive acoustic signal from a sound source placed at far field distance (Plane Wave) and from broadside. I receive output of these sensors through individual preamplifiers, add them through hardware like summer circuit adder or in software after digitization and in this way got an...
View full post »

Thread 'Following up on the recent thread about Earth Resistance measurements'

I have recently moved into a new (rather ancient) house and had a few trips of my Residual Current breaker. I dug out my old Socket tester which tell me the three pins are correct. But then the Red warning light tells me my socket(s) fail the loop test. I never had this before but my last house had an overhead supply with no Earth from the company. The tester said "get this checked" and the man said the (high but not ridiculous) earth resistance was acceptable. I stuck a new copper earth...
View full post »

Thread 'Question about bonding ground and neutral'

I am not an electrical engineering student, but a lowly apprentice electrician. I learn both on the job and also take classes for my apprenticeship. I recently wired my first transformer and I understand that the neutral and ground are bonded together in the transformer or in the service. What I don't understand is, if the neutral is a current carrying conductor, which is then bonded to the ground conductor, why does current only flow back to its source and not on the ground path...
View full post »

Similar threads

Odd box that connects to alternator and produces 120 volt DC....
Replies
22
Views
2K
Question about the voltage between two charged capacitors
Replies
4
Views
130
Resistive heating power AC vs rectified AC/DC
Replies
10
Views
4K
12V DC Motor in Light Fixture with Dimmer & 12V DC to 110V AC Inverter
Replies
21
Views
2K
Variable vs constant power supply
Replies
32
Views
2K
"Ground" and "Center Tapped" Power Transformer Secondary in guitar amp
Replies
6
Views
3K
AC to DC voltage doubler not working
Replies
7
Views
4K
Making a Step-up DC transformer
Replies
4
Views
2K
DC to DC boost converter malfunctioning
Replies
9
Views
4K
Self Excited AC Single Phase Generator
Replies
12
Views
5K

Hot Threads

Recent Insights

Back
Top