# Power Supply Problem: 19V 3A Laptop Charger + Solenoid

• Anugrah_kora
In summary, you need to use a load of about 19V/3A = 6.3 Ohms to keep the output from being in current limit.
Anugrah_kora
I've got an old laptop charger 19v 3A for my solenoid.
I used a multimeter to check the charger without and with load. I used a solenoid of insulated 22gauge of approx 150 turns as the load. On my first try without any load, it gave 20v DC on the multimeter.
When I connected the load and connected the multimeter ,it gave values on AC part fluctuating back and forth from 0-1.5v . Can anyone help me out in this? Is there anyway to get DC out of it while on load ?

Anugrah_kora said:
I've got an old laptop charger 19v 3A for my solenoid.
I used a multimeter to check the charger without and with load. I used a solenoid of insulated 22gauge of approx 150 turns as the load. On my first try without any load, it gave 20v DC on the multimeter.
When I connected the load and connected the multimeter ,it gave values on AC part fluctuating back and forth from 0-1.5v . Can anyone help me out in this? Is there anyway to get DC out of it while on load ?
You are shorting out its output, so it is in current limit until you remove the short.

You need to put a load of about 19V/3A = 6.3 Ohms on it to keep it out of current limit.

berkeman said:
You are shorting out its output, so it is in current limit until you remove the short.

You need to put a load of about 19V/3A = 6.3 Ohms on it to keep it out of current limit.
I tried 6ohms ( I don't remember correctly,but it's close to 6ohms) and the solenoid literally ceased to function :(

Anugrah_kora said:
I tried 6ohms ( I don't remember correctly,but it's close to 6ohms) and the solenoid literally ceased to function :(
What wattage resistor did you use? I^2 * R = 54W, so you would have needed a pretty big power resistor...

#22 is 16 milliohms per foot.

How many feet of #22 would it take to make six ohms ?
On your solenoid's diameter, how many turns would that be ?

Do you understand the relation between amp-turns and magnetic field strength ?
You might look that up . Train your search engine - it wants to please .

berkeman
Anugrah_kora said:
I tried 6ohms ( I don't remember correctly,but it's close to 6ohms) and the solenoid literally ceased to function :(

not surprised ... your LOAD, the coil, needs to be around 6 Ohms ... not a 6Ohm resistor in series with it Dave

berkeman

## What is the meaning of 19V 3A in a laptop charger?

The 19V 3A in a laptop charger refers to the voltage and amperage specifications of the charger. It means that the charger is able to supply a constant voltage of 19 volts and a current of 3 amps to the laptop.

## What can cause a power supply problem in a laptop?

There are several potential causes for a power supply problem in a laptop. It could be due to a faulty charger, damaged charging port, or a problem with the laptop's internal power circuitry. Additionally, using a charger with incorrect voltage or amperage can also lead to power supply issues.

## What is a solenoid and how does it relate to a power supply problem?

A solenoid is an electromagnetic device that converts electrical energy into mechanical motion. In the context of a power supply problem, a solenoid is often used to regulate the flow of electricity and ensure that the correct voltage and current are being supplied to the device. If the solenoid is malfunctioning, it can cause fluctuations in the power supply, leading to issues with the laptop's performance.

## How can I troubleshoot a power supply problem with a 19V 3A laptop charger?

If you are experiencing a power supply problem with your laptop charger, there are a few steps you can take to troubleshoot the issue. First, check the charger and make sure it is functioning properly. Next, inspect the charging port on your laptop for any damage or debris that may be preventing a proper connection. If the issue persists, it may be a problem with the laptop's internal power circuitry and you may need to seek professional assistance.

## Is it safe to use a charger with different voltage or amperage specifications?

No, it is not safe to use a charger with different voltage or amperage specifications than what is recommended for your laptop. Using the wrong charger can damage your device and potentially cause safety hazards. Always make sure to use the correct charger for your laptop to ensure proper power supply and avoid any potential problems.

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