Opps.. yes, here is the link: http://www.newark.com/webapp/wcs/stores/servlet/Search?catalogId=15003&langI d=-1&storeId=10194&categoryId=800000005767&pageSize=25&showResults=true&aa=t rue&pf=811258226,811258357,811258459,811258482,811258565,811258569,811258571 ,811258603,811258616,811258623,811258725,811258765,811258780,811258874,81125 8885,811258925,811258941,811258947,811258982,811258987,811259023,811259065,8 11298108,811298109,811298494,811353625,811437188,811437191,811985601,8120376 50&min=811258765,811258947&max=811258780,811258357
Not too expensive, easy to connect, regulated and 500mA -----Mensaje original----- De: EV [mailto:[email protected]] En nombre de Cor van de Water via EV Enviado el: sábado, 25 de julio de 2015 11:36 a.m. Para: Electric Vehicle Discussion List Asunto: Re: [EVDL] 48V Energy Meter (Lead-Acid)... Marco, the link was missing in the post I received. Damon, As others have said - this is a non-isolated solution to power the meter. However, if you power the meter from the traction pack, the meter does *NOT* connect the traction pack to ground, so a non-isolated solution is not a problem as long as you take care wiring the meter correctly: don't wire it to ground = chassis but only to the traction pack + and - so the meter will float with the pack. This is different than using a 12V input to power the meter, since the 12V negative is always connected to ground (chassis) so in that way, you connect the traction pack through the meter. At 48V it is possible that the traction pack negative is anyhow connected to chassis, but this is not guaranteed and it is better to connect the meter to the pack anyway. Note that the zener drops a fixed voltage in *reverse* direction (in forward direction it is just another diode) so you need to calculate the highest and lowest voltage that your pack is reaching and see if that stays in spec for the meter. For example a lead-acid pack may go from 36V on acceleration while empty (1.5V per cell) to 60V on equalization charge (2.5V per cell) This means that a 25V to 27V drop will give you power for the meter, but any larger swings and the meter will not work and a DC/DC is better: with a 27V zener, the meter supply voltage goes from 9V to 33V on that swing. Yes, a series fuse or resistor is highly recommended. In fact, to protect your meter it is a good idea to have a 33V zener across the meter as well, so that if the power supply goes too high, it starts drawing more current and drop it across the series resistor in the supply line. Normally the voltage on the meter will be below that zener's voltage and no extra current will flow, that is why I recommend a zener as dropping element, not a resistor. A slightly fancier setup is to use a transistor that can withstand a higher voltage than the pack can reach and which drops the voltage to a level that the meter can work with so you extend the meter's linear regulator's voltage input range externally. My reason to use a dropping zener or linear regulator (while I am fanatic about efficiency) is that the meter draws a very small current, so even a DC/DC converter will have low efficiency and I doubt that it will draw less current than when simply dropping voltage with a zener, but that will depend on the quality of your DC/DC. The other reason is that a zener is cheaper than a DC/DC converter. Hope this clarifies, 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: Sat 7/25/2015 9:43 AM To: 'Robert Bruninga'; 'Electric Vehicle Discussion List'; 'damon henry' Subject: Re: [EVDL] 48V Energy Meter (Lead-Acid)... Thanks to all for your recommendations. Rush, yes.. I have 2 of them thanks to you :), but the owner of the vehicle I'm going to use the meter wants something that tells him in 'percentage' an E-meter only has 4 LED lamps. Cor, yes you are right; Xantrex is the new name of the E-Meter product, and yes the new one works only up to 35V, but tech manual does not says at any place where to move the decimal point or another different voltage value reading. Maybe they just took out that feature on this new models. Damon, an isolated power supply Cannot be done by just using a Zener diode, that would be non-isolated and could work fine for your motorcycle as long as you share grounds for 48V and 12V for your e-meter. But just as Robert says; you would waste more energy on the (48-12V = 36) 36Volts side in heat all time, than the power the meter consumes itself. You'd better use a mini 'switched power supply'. Some products like this ones would work perfectly (especially the first result): Saludos... Ing. Marco Gaxiola CEO/Director Juarez #18, Col. Bachoco Tel: +52(662)301.1070 Skype: info.energyev www.energyev.com -----Mensaje original----- De: EV [mailto:[email protected]] En nombre de Robert Bruninga via EV Enviado el: sábado, 25 de julio de 2015 07:50 a.m. Para: damon henry; Electric Vehicle Discussion List Asunto: Re: [EVDL] 48V Energy Meter (Lead-Acid)... 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-batter > y-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/20150724/750 > 52e4f/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/20150725/4e0 > cef71/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... 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