Power Saving DC Solenoid Driver Provides Initial Full Power Actuation Followed By PWM Hold 2018-03-31

[crutschow]

crutschow submitted a new article:

Power Saving Solenoid Driver Provides Initial Full Power Followed By 555 PWM Hold - Circuit applies full power to energize solenoid followed by low current PWM hold using 555 timer

To save power and reduce temperature rise, a solenoid or relay coil is often initially energized with full power to rapidly complete the solenoid stroke and then the current is reduced to just what's required to hold the solenoid in.
The most efficient method to lower the current is with a PWM (Pulse Width Modulated) signal with duty-cycle selected to give the desired hold current.
This can also be used to apply an initial overvoltage to the solenoid for more rapid operation, and then drop...

 

[Frozenguy]

Is it just me or broken link?

I have used an economizer circuit from TI to run contactors that were pulling 15 W but now pull about 3.5 W.

 

[crutschow]

Is it just me or broken link?

It's the link.
The site automatically generates this thread when I add a new article and it adds a bogus link.
I corrected the link.

 

[KeepItSimpleStupid]

I've done both. The kick followed by a hold and slow-engaging.

The "kick" followed by a hold, although in that design I used a big heat sink. There was plenty of cooling around since this was a lamp housing for a fiber light. It was also a rotary solenoid which seem to always require the kick method.

The slow engaging again was a light shutter. When the solar simulator came back from being repaired and modded, the manual shutter became electric, butit was close to a $1000 1 mm thick glass filter. Activation would be for about 30s every 2:30 minutes or so. Turned out a Velleman PWM kit **broken link removed** fit the bill perfectly because of "slow-start" built in.