You must have a series current limiting resistor. The disadvantage of any zener power supply/regulator is that you are wasting all the drop-down voltage as heat. So for a 12v zener from 48v, only 1/4th of the power drawn actually goes into the device. The rest is wasted.
bob On Sat, Jul 25, 2015 at 9:20 AM, damon henry via EV <[email protected]> wrote: > Hi Cor, > I have been around and using E-meters for many years now and this is the > first time I have ever heard of using a zener diode as a method to create > an isolated power supply for one. Is it really that simple? If so I might > switch to this on my motorcycle (48v). I currently have a small 12 volt > battery that I use just for running my meter, which is a pretty simple > setup, but does require me to charge the battery once a week, and/or > disconnect the battery if I leave the motorcycle unused for a long stretch. > If I understand this method I would simply connect the emeter power > through a zener diode off my traction pack and that would provide both the > required isolation and enough of a voltage drop to keep from burning the > meter out. That sounds easy :) Do you just wire the zener into one of the > power leads from the traction pack to the emeter? Does it matter whether > it is on the positive or negative lead? Are there other components that > could/should be added like a fuse or current limiting resistor? > thanksDamon > > > Date: Fri, 24 Jul 2015 23:15:24 -0700 > > To: [email protected] > > Subject: Re: [EVDL] 48V Energy Meter (Lead-Acid)... > > From: [email protected] > > > > The older (pre-decessor or just re-packaged?) Link 10 meter from Xantrex > > was also limited to 35V (it is the 7800-series linear voltage regulator > max input) > > so a 1:10 pre-scaler could be used to measure higher voltage, while > powering the > > unit from an isolated power supply between 12-35V although if it is just > 48V as in your case, > > the prescaler is needed but the power supply can simply be a zener > diode, dropping the > > 48V (max charge voltage for example 60V so you would need a 25V or next > higher zener) > > > > If I am not mistaken, the Link 10 had a software feature to shift the > decimal dot a place > > so you could take the 10:1 pre-scaler into account in Voltage and energy > measurements. > > Not sure if this unit has that same feature - Lee might know as he has > made a > > companion board for the Link 10. > > > > Regards, > > > > Cor van de Water > > Chief Scientist > > Proxim Wireless Corporation http://www.proxim.com > > Email: [email protected] Private: http://www.cvandewater.info > > Skype: cor_van_de_water XoIP: +31877841130 > > Tel: +1 408 383 7626 Tel: +91 (040)23117400 x203 > > > > > > > > -----Original Message----- > > From: EV on behalf of Ing. Marco Gaxiola via EV > > Sent: Fri 7/24/2015 11:08 AM > > To: 'Electric Vehicle Discussion List' > > Subject: [EVDL] 48V Energy Meter (Lead-Acid)... > > > > > > I'm looking for an energy meter for a lead-acid 48V (Nominal) > bank. A friend recommended me this one from Xantrex: > > > > > http://www.xantrex.com/power-products/power-accessories/linkpro-battery-monitor.aspx > > > > that looks great and ideal for my Project. But unfortunately maximum > reading voltage is up to 35Vdc. (although using a pre-scaler in the input > voltage and a 48V to 12V DC-DC power supply; the firmware parameters in the > programming options of the device, according to the datasheet; are only up > to 35Volts range) > > > > if someone does know of a similar product solution that could be > recommended, please advice. > > > > > > (Application: It's intended to be used on an Electric Polaris > Vehicle. I'm upgrading the battery pack, extra charger and adding some > solar panels in order to improve range, charge time and ability to slowly > self-recharge while in the sun. To be used on a Ranch.) > > > > > > Ing. Marco Gaxiola > > CEO/Director > > Juarez #18, Col. Bachoco > > Tel: +52(662)301.1070 > > Skype: info.energyev > > www.energyev.com > > > > > > > > > > --- > > El software de antivirus Avast ha analizado este correo electrónico en > busca de virus. > > https://www.avast.com/antivirus > > > > _______________________________________________ > > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > > For EV drag racing discussion, please use NEDRA ( > http://groups.yahoo.com/group/NEDRA) > > > > > > -------------- next part -------------- > > A non-text attachment was scrubbed... > > Name: not available > > Type: application/ms-tnef > > Size: 4207 bytes > > Desc: not available > > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20150724/75052e4f/attachment.bin > > > > _______________________________________________ > > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > > For EV drag racing discussion, please use NEDRA ( > http://groups.yahoo.com/group/NEDRA) > > > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20150725/4e0cef71/attachment.htm > > > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > For EV drag racing discussion, please use NEDRA ( > http://groups.yahoo.com/group/NEDRA) > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20150725/b060c3ae/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
