Larry, A latching relay isn't suitable for fail-safe applications. Look into the "Kilovac Czonka III EV200HAANA". This series has a coil "economizer" that reduces coil current (and thus power consumption) after pull-in. Rated coil power is less than 2 watts. Models are good to 900Vdc and up to 500A. Coil inrush current on one model I found is spec'd at 3.8 A for a 130 milliseconds, so you'd need an external transistor to drive it from the computer. If power consumption is a critical aspect, use a suitable MOSFET. If you don't mind wasting another watt or two, a bipolar NPN will also work. The coil current throttles back to less than 100 mA at 12Vdc after contact closure. Because a specialized electronic power supply is driving the coil, Kilovac rates the DC input to the coil driver at anything from 9Vdc to 36Vdc. Here's the Allied page: http://www.alliedelec.com/search/productdetail.aspx?SKU=70062411 Not cheap .. but excellent quality. If you're a registered reseller with Allied, the $ is less. Dan
-------------------------------------------- On Tue, 2/11/14, Larry Crutcher, Starlight Solar Power Systems <la...@starlightsolar.com> wrote: Subject: [RE-wrenches] DC Solenoid Coil Current To: "RE-wrenches" <re-wrenches@lists.re-wrenches.org> Date: Tuesday, February 11, 2014, 6:43 PM Hello Wrenches, We're preparing to offer Lithium batteries to some of our customers as a replacement to lead acid in recreational vehicles. RV batteries can have multiple charge sources simultaneously so I have worked out protective circuitry to interface with a EMS computer. To insure failsafe operation, I need to install 2 solenoids that will be active 24/7, opening only when fault conditions are met. The solenoids I have looked at (200 amp) have a coil current of about 1 ampere each which equates to 600Wh daily consumption. I'de like to reduce that BUT the computer only provides a +12v or 0 volt state. * Does anyone know of a latching solenoid that will work with a 12v hi/lo voltage state, * OR an interface or circuit for hi/lo to control latching relay * OR a solenoid with a very low quiescent current when on? Many thanks in advance, Larry Crutcher _______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
