Noob in the field -- problems making a solenoid....

AI Thread Summary
A group is attempting to build a solenoid using 22 gauge insulated wire and a 19V, 3.3A laptop charger. They initially used a 1A power supply, which was insufficient, and encountered issues with the solenoid reversing current direction. Suggestions include the possibility of the charger having circuitry that prevents shorting and the need for a resistor in series. However, adding a 1.5-ohm resistor caused the solenoid to stop functioning entirely. The discussion highlights the importance of matching the load resistance to the power supply specifications for proper operation.
Anugrah_kora
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Hello.
Me and my friends planned to make a solenoid. We used 22 gauge insulated wire and we used an old laptop charger (19v 3.3A) as the power supply. Earlier we used a power supply of 1A and it wasn't enough. When we connected everything and switched on,we saw the solenoid behaving weirdly . We found out that it was changing the direction of the current flow causing it to act like this. I don't know if it is the charger..
Please can someone help me?
 
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Could it be that the power supply has some circuitry which prevents shorting the output? Maybe you need to put a resistor in series with your solenoid.
 
scottdave said:
Could it be that the power supply has some circuitry which prevents shorting the output? Maybe you need to put a resistor in series with your solenoid.
Tried adding a 1.5ohms resistor in series but the solenoid ceased to function.. :(
 
What is the DC resistance of your solenoid? Based on your data the charger needs to have at least 19/3.3 = 6 Ohms load - or 120 feet of 22 Ga ( 22 ga = 0.05 Ohms per foot)...
 
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