user12100: I wish to use an arduino like this with a 12v solenoid lock like this. How can I do this. I am told that using this might work, but I am also thinking I can use a transistor's amlification to do that. Can you tell which one is better and if transistor, how to do that?

user13669: By sheer luck your lock solenoid looks very similar to this one (similar spec too "Draws 650mA at 12V") and they have a working circuit for it over here so look at that and see what they used to drive it. Apparently it's a TIP120, so the peak/draw current is probably higher than that ballpark figure, which I suspect is for the hold.


Overengineering the transistor by an order of magnitude or so (for a poorly spec'd solenoid part) ensures it doesn't go pop so easily. Also, a Darlington like TIP120 is very easy to drive from the arduino or some other microcontroller.
A similar project using the same solenoid lock used an IRLB8721 (power MOSFET) instead, which is even more beefy in terms of load current it can handle.

12100: <p>I wish to use an arduino like <a href="http://www.snapdeal.com/product/arduino-uno-r3-board-with/566147335" rel="nofollow">this</a> with a 12v solenoid lock like <a href="http://www.ebay.in/itm/331401195916?ssPageName=STRK:MEWNX:IT&amp;_trksid=p3984.m1439.l2649" rel="nofollow">this</a>. How can I do this. I am told that using <a href="https://www.sparkpcb.com/development/l293-d-dc-motor-driver-board.html" rel="nofollow">this</a> might work, but I am also thinking I can use a transistor's amlification to do that. Can you tell which one is better and if transistor, how to do that?</p>
 13669: <p>By sheer luck your lock solenoid looks very similar to <a href="https://www.adafruit.com/products/1512" rel="nofollow noreferrer">this one</a> (similar spec too "Draws 650mA at 12V") and they have a working circuit for it <a href="https://learn.adafruit.com/secret-knock-activated-drawer-lock" rel="nofollow noreferrer">over here</a> so look at that and see what they used to drive it. <a href="https://learn.adafruit.com/secret-knock-activated-drawer-lock/parts-and-tools" rel="nofollow noreferrer">Apparently</a> it's a TIP120, so the peak/draw current is probably higher than that ballpark figure, which I suspect is for the hold.</p>

<p><a href="https://i.stack.imgur.com/5ptTr.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/5ptTr.jpg" alt="enter image description here"></a>
<a href="https://i.stack.imgur.com/PNupP.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/PNupP.jpg" alt="enter image description here"></a></p>

<p>Overengineering the transistor by an order of magnitude or so (for a poorly spec'd solenoid part) ensures it doesn't go pop so easily. Also, a Darlington like TIP120 is very easy to drive from the arduino or some other microcontroller.</p>

<p><a href="https://learn.adafruit.com/remote-controlled-door-lock-using-a-fingerprint-sensor-and-adafruit-io/setting-up-the-electronic-door-lock" rel="nofollow noreferrer">A similar project</a> using the same solenoid lock used an IRLB8721 (power MOSFET) instead, which is even more beefy in terms of load current it can handle.</p>
