Screw on VoltMeter ! $10.95

hagstrom · 12-21-2010, 09:37 PM

Yes a screw on voltmeter , good for any PV

berger · 12-22-2010, 08:49 AM

Does that work as unloaded voltmeter only?
Any idea level of accuracy at anticipated voltages?

hagstrom · 12-23-2010, 02:59 AM

Yes it is unloaded , you could solder a resistor on it 2-3.3 ohms or ?? to test under load .

Accuracy is .005-/+volts

not bad for a small meter and more than good enough for an E cig

tek · 12-23-2010, 04:42 AM

Can you add a connector and cord so we can see what we vape.

hagstrom · 12-23-2010, 04:44 AM

you could mod it like that , we will not be doing that but it would be easy

tek · 12-23-2010, 04:48 AM

Yes it would and I thought it might be a good angle for ya. If it came like that id order one right now.

Rocketman · 12-23-2010, 08:28 AM

Quote:

Originally Posted by hagstrom

Yes it is unloaded , you could solder a resistor on it 2-3.3 ohms or ?? to test under load .

Accuracy is .005-/+volts

not bad for a small meter and more than good enough for an E cig

Hag,
it looks like it has three digits.
accuracy of .oo5 volts?
Like for 3.700 volts it will display 3.995 to 3.705?
and for 3.000 volts it will display 2.995 to 3.005?
or will it read that low?
Rocky

berger · 12-23-2010, 11:16 AM

.005 volts make sense. +or- registers as .01 or .00 in this case
I think

Rocketman · 12-23-2010, 11:36 AM

Accuracy tolerance is the probability that an indicated reading will be within a percentage of the "true" value. With digital devices this is a function of accuracy, stability (temperature and time ) of the analog to digital converting circuitry, ranging resistors and system noise. For a 20 volt 4 and a half digit meter for example capable of indicating 19.999, the accuracy may be +/-( 0.01% of full scale plus 0.01% of indication, plus 1 digit). 5.000 volt indication could be between 4.9965 and 5.0035 actual volts. This would be a pretty good 4 1/2 digit meter, not a Harbor Freight special.
A good 3 1/2 digit meter, Fluke 8020 for example is primarily limited by display resolution. Process controls used by a large manufacturer like Fluke has allowed them to improve component accuracy to better than display capabilities. Their spec was simplified because of this to +/-(0.1% of reading + 1digit) for a period of one year from calibration date for the 2 volt and 20 volt DC ranges. Other ranges and functions are not as good. A 5.00 volt indication would be between 4.985 to 5.015 actual volts. Calibration even tests rollover from 9.99 to 10.00 to verify midscale accuracy to better than display capability. The newer model 177 3 1/2 has a +/- (0.09%Reading +2LSD) spec.

The screw on is 3 times better than an 8020?

Rocketman · 12-23-2010, 12:22 PM

If my previous post sounds negative, sorry, not meant to be.
As I've said many times, if you have a mod, especially a stacked battery mod, you need a meter. If you use LR attys/cartos, you need a meter. If you don't have one buy one.
This screw on (indicates unloaded voltage) would be a big help adjusting or troubleshooting a HV mod. The voltage indication would be more than accurate enough for vaping.
I do have a couple of questions:
Since it is probably powered from the connector (no internal battery), what is the lowest voltage it can indicate?
and, how well does it display voltage from a 510, or ego, or PigCig, which aren't pure DC output straight from the battery?

berger · 12-23-2010, 12:26 PM

For 10 bucks I doubt seriously.... perhaps 1/2 % accuracy? and display in 1/10 ths?

Sorry you reposted before I did

I was looking at this more from a mod utilization and an indicator on the fly type of thing especially with tractor trailer batteries, not so much for use a as replacement to a multimeter you'd need for ohms anyway.

About the part concerning the voltage output on egos ets. is that due to the protection circuit or is there something else going on there?

Rocketman · 12-23-2010, 12:33 PM

The decimal point is probably scaled to indicate 2 decimal places. The +/- 0.005 volts spec means it is pretty much "dead on" throughout it's range. That's a pretty optimistic spec for 95% of the production run. But, what is the accuracy when you get down closer to the lower voltages, like 4 v, or 3.7, or 3.2? Will it turn on at 3.2?

Indicating 5.02 when the mod is really set for 5.00 is not an issue for vaping. One or two display counts don't hardly matter when checking batteries fresh off the charger either.

If someone has a high voltage mod and don't think they could operate a regular DMM, this would be pretty handy.

berger · 12-23-2010, 12:39 PM

gee a spec sheet would be useful here but I doubt it

hagstrom · 12-23-2010, 01:45 PM

Rocketman has it right it has 2 dec.
I don't even get spec sheets LOL !

they are designed for RC applications with multiple batteries , the lowest voltage is right around 3.0 volts

berger · 12-23-2010, 01:55 PM

Thanks Hagstrom
Im going to get one of those from you

hagstrom · 12-23-2010, 01:56 PM

No problem Berger , they are a nice little pocket volt meter

berger · 12-23-2010, 05:10 PM

Order placed,
maybe do a review in a week or so

hagstrom · 12-23-2010, 05:31 PM

All right Cool , let us know how you like it

BTW If you want to test loaded voltage either box it and add another conn. or solder a 3 or 2.5 ohm load res. to the leads ( you would need a 5 watt res. min. )

berger · 12-23-2010, 10:15 PM

Thanks,
I think eventually I want to box it into a mod.

hagstrom · 12-23-2010, 10:51 PM

that works too

Rocketman · 12-28-2010, 11:54 AM

This little voltmeter may need a little modification to be useful to some of us ego type vapers.
THe power to run this comes from the e-cig, not much, but trying to draw current and measure it at the same time reduces the meters input impedance. Normal DMMs have a 10 megohm input impedance but run off internal batteries. This device may draw a small current of 10 ma. An input filter may need to be added to filter the pulsed voltage from e-cigs like the ego. Just guessing, but a 10uf electrolytic capacitor across the input may be enough. Voltage indication will be lower than actual because the device is also drawing power from the filter. A larger capacitor may present a damaging load to the e-cig. Haven't tried with this voltmeter. Maybe the supplier could test this, or send me one and I'll test it and reply (gratis).

Rocky

berger · 12-28-2010, 01:15 PM

Thanks, now I know what to do to try and make it work on an ego
Time to pull out the kids new electronics kit he got for christmas

hagstrom · 12-28-2010, 02:30 PM

Could be Rocky I dont have an EGO or similar device , BUT why would you even want to measure an EGO ???? its 3.2 volts pulsed !!!
( from what Cisco measured with an O scope )

Rocketman · 12-28-2010, 02:33 PM

Actually measuring voltage would be a troubleshooting method for any e-cig. Some just swap and kill parts until they run out of stuff

If you have a VV then you could set unloaded voltage which would be close to loaded voltage if the regulator is still working.

Either way, a meter is a handy thing to have.

berger · 12-28-2010, 02:40 PM

Excusing me for jumping in here but Hagstom I asked him about it as I didnt know it was pulsed. I bet in case other electrical noobs like me here might buy it expecting to work on an ego not knowing that they were pulsed.