Expanded scale voltmeter, which one?
#1
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From: San Antonio,
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Ok,,I'm going to purchase an expanded scale voltmeter, but need your help to decide which one. I'm leaning towards the Hobbico Digital for the ease of the readout and the on/off load feature. I do see the analogs are a bit less expensive though. What are you all using? I did see the "how to make your own" write up on Red's wesite, but I hate to solder and would rather spend a few dollars for the insurance of knowing it's working as it should.
Any suggestions/comments?
thanks,
Any suggestions/comments?
thanks,
#2
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From: Oklahoma City,
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I like the digital voltmeter for the ease of reading but the thing I like about the analog is the fact I don't have to remember what voltages are safe. It has a green area on the scales that tell me what is the safe ranges for the different battery types. I don't even have to think about whether it is safe to fly or not. Just make sure you use it after every two or three flights. I forgot once. . . .
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From: Jacksonville,
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I use this one...
http://www2.towerhobbies.com/cgi-bin...?&I=LXNK81&P=7
I check the battery right after a flight just to be sure all is well. I also like the analog with colored bars and not a digital readout. I have been using this meter for a year now and would not feel comfortable without it.
http://www2.towerhobbies.com/cgi-bin...?&I=LXNK81&P=7
I check the battery right after a flight just to be sure all is well. I also like the analog with colored bars and not a digital readout. I have been using this meter for a year now and would not feel comfortable without it.
#4
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From what I understand (please correct me if I'm wrong) when flying with a 4.8v pack, anything 4.8v and above is safe to fly with. So that being known, with the analog one, would it be safe to assume that anything in the white area is safe to fly with also?
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From: Jacksonville,
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Yes, anything above 4.8 is good to go. If you look at a battery discharge plot, you will see that the battery will begin at 5.3 - 5.5 volts and drop down to 4.8 - 4.9 within the first, say 10 minutes. The battery will hover around 4.8 for a lllooonnnggg time, but at around 4.6 volts, the plot starts to drop pretty quick. Gotta love that Orbit Microlader.
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From: W. Bloomfield,
MI,
Cruz
I have been using the Hobbico Digital Voltmeter. It tells you when the battery is low with a flashing message. I was told these batteries are good usually for about four or five flights then need recharging. This was my experience last night.
Michael
I have been using the Hobbico Digital Voltmeter. It tells you when the battery is low with a flashing message. I was told these batteries are good usually for about four or five flights then need recharging. This was my experience last night.
Michael
#8
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I have not found the analog to be accurate for me . Have an old ACE one that is close . Digital , I just check against my shop lights , two bladed prop = 3600 RPM & it has load & lights , Hobbico. Too many moving parts in analog ! MAX H.
#12
I suggest a digital multimeter - and not the kind made specifically for RC. Get a DMM from Radio Shack, Home Depot, Harbor Freight, or wherever for $10-$20. Add your own 20 ohm 2 watt load resistor from Radio Shack. This method will be no more expensive and much more useful and more accurate than an ESV. Search the old posts or check Red's site for more info. Use stackable banana plugs and you will only need to make two easy solder joints.
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From: Milton Keynes, UNITED KINGDOM
Originally posted by big max 1935
I have not found the analog to be accurate for me . Have an old ACE one that is close . Digital , I just check against my shop lights , two bladed prop = 3600 RPM & it has load & lights , Hobbico. Too many moving parts in analog ! MAX H.
I have not found the analog to be accurate for me . Have an old ACE one that is close . Digital , I just check against my shop lights , two bladed prop = 3600 RPM & it has load & lights , Hobbico. Too many moving parts in analog ! MAX H.
#15
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From: San Antonio,
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I already have a multimeter. Ok,,,,so I walk into RS and tell 'em I need a 10 ohm 2 watt load resistor. Then I solder it between the two leads and I'll be set?
#17
Cruzomatic,
Yes, that is all there is to it. Make it a 20 ohm 2 watt resistor. I had a mistake in my original post, which I have since corrected. This will give you about 250 ma on a 4.8 V pack, which is about what you want.
If your DMM has banana plug leads (most do) and you have a Rx charge cord with banana leads then it is handy to solder a set of stackable banana plugs (available from Radio Shack) on the resistor. They allow you to stack the charge jack on top. Just solder a plug on each lead of the resistor. Plug your charge jack on top of each of the resistor's plugs and plug the assembly into your DMM. If you ever need to check the battery pack voltage without the load then just unplug the resistor, etc.
Yes, that is all there is to it. Make it a 20 ohm 2 watt resistor. I had a mistake in my original post, which I have since corrected. This will give you about 250 ma on a 4.8 V pack, which is about what you want.
If your DMM has banana plug leads (most do) and you have a Rx charge cord with banana leads then it is handy to solder a set of stackable banana plugs (available from Radio Shack) on the resistor. They allow you to stack the charge jack on top. Just solder a plug on each lead of the resistor. Plug your charge jack on top of each of the resistor's plugs and plug the assembly into your DMM. If you ever need to check the battery pack voltage without the load then just unplug the resistor, etc.
#18

This is the one I use, can test with load or without, A regular multi meter can not test with load and if the battery needs charging it tells you to charge or tells you OK to fly http://www2.towerhobbies.com/cgi-bin...?&I=LXWW16&P=7
#22
Here are some photos of my loaded DMM. The DMM is a cheapo that I got on sale for $5 from Harbor Freight. It is a tiny thing measuring 1.5 x 4.5 inches but I checked it against a Fluke and it agrees to within 1/100 volt at 4.8 volts. It also measures resistance, ac voltage, ac and dc current, etc. Real handy to have around the house if you don't already have one.
The load is a 18 ohm 2 watt resistor (color code brown, gray, black). This is suitable for use with a 4.8 V receive pack and will draw about 270 mA. I soldered stackable banana plugs onto the resistor, which are available from Radio Shack for around $2. I used insulated wire and shrink tubing to connect the bare wires coming off the resistor to the banana plugs, but this is not necessary. You could just as well put the banana plugs directly onto the resistor's leads. The charge jack is from Radical RC and comes with the banana plugs attached. I think it costs around $3.
The resistor is not polarized - it doesn't matter which way you connect it.
The load is a 18 ohm 2 watt resistor (color code brown, gray, black). This is suitable for use with a 4.8 V receive pack and will draw about 270 mA. I soldered stackable banana plugs onto the resistor, which are available from Radio Shack for around $2. I used insulated wire and shrink tubing to connect the bare wires coming off the resistor to the banana plugs, but this is not necessary. You could just as well put the banana plugs directly onto the resistor's leads. The charge jack is from Radical RC and comes with the banana plugs attached. I think it costs around $3.
The resistor is not polarized - it doesn't matter which way you connect it.
#24
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From: San Antonio,
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nice pics, but I'm confused a bit.
In pic #1 the resistor is connected between (+) and (-). In pic #2 it looks as if it's connect b/w two (-)'s.
In pic #1 the resistor is connected between (+) and (-). In pic #2 it looks as if it's connect b/w two (-)'s.
#25
The picture doesn't show it as clearly as I had hoped. One resistor plug is connected to the "common" socket of the DMM and the other resistor plug is connected to the "V" socket of the DMM. The charge jack plugs in on top of the resistor plugs. One plug of the charge jack plugs in on top of the "common" resistor plug. the other plug of the charge jack plugs in on top the "V" resistor plug.


