# Increase Force of a Solenoid

I tried to build a circuit that would allow me to push a washing machine's start button remotely using a solenoid as an actuator.

The solenoid is wired to a 9v battery which also powers an ESP8266 through LM7805 voltage regulator.

Unfortunately, after soldering all the components, I discovered that the soleniod does not produce enough force to actually push the button.

The solenoid I used has the following parameters (sellers ebay page):

Rated Voltage & Current DC 6V 0.15A
Power   3.4W
Action Form Push Pull Type
Force
Stroke: 2mm 35g/0.08lb
Stroke: 1mm 80g/0.18lb
Power On Type   Intermittent 25%
Max Power On Time   1 Second
Body Size   20 x 12 x 11mm/0.8" x 0.5" x 0.4"(L*W*H)
Cable Length    5cm/2"
Material    Metal, Electronic Parts
Weight  14g
Package Content 1 x DC Solenoid Electromagnet


simulate this circuit – Schematic created using CircuitLab

I don't want to desolder anything. The solenoid and battery are connected with plugs into the board so I can replace them easily.

My question is: having these constraints, is there anything I can do to increase the force of the push?

Maybe I can replace the solenoid with a different one? Or plug something else instead of it? Can plugging different power source help?

• Use a power source that can deliver more power than a 9V battery. 150 mA is actually quite a strain for that type of battery, which was designed for circuits that require 10-20 mA at most. – Dave Tweed Jun 19 '16 at 20:42
• * I'ld suggest to measure the consumption that you currently have and you'll probably coerce Dave's comment. * I am surprised that the coil is rated 6VDC and 0.15A which is under 1W while it is supposed to consume almost 4W? * The 6V rated voltage may be compatible with the fact that the battery can't drive the load. * If you have a 9V adapter that can deliver 0.15A, you can check if the circuit works with a better power source (and measure the characteristics). – le_top Jun 19 '16 at 20:55
• Use large capacitor such as 68000uF in parallel to the battery might give enough current strength to do the job. However yr transistor may need to upgraded to low on-resistance MOSFET. – soosai steven Jun 19 '16 at 20:57
• @DaveTweed What will be the effect of these suggestions on the LM7805 that is connected to the same power source? – Artium Jun 20 '16 at 18:08
• @soosaisteven What will be the effect of the suggestion on the LM7805 that is connected to the same power source? – Artium Jun 20 '16 at 18:09