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

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SUMMARY

The discussion centers on troubleshooting issues with a solenoid powered by a 19V, 3.3A laptop charger. Users initially attempted to use a 1A power supply, which was insufficient. The solenoid exhibited erratic behavior, likely due to the charger’s internal circuitry preventing short circuits. Suggestions included adding a resistor in series, but a 1.5-ohm resistor caused the solenoid to stop functioning. The required load for the charger is calculated to be at least 6 ohms, equating to approximately 120 feet of 22-gauge wire.

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  • Knowledge of electrical resistance and Ohm's Law
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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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