Need Help Adding a Voltmeter
- Thread starter Cold Beer
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dcyrilc
Elite Member
Hey Paul,
What's the white button on the shaft of the FEL joystick? That parking brake light looks good too. I think this is the first pic that I've noticed it installed.
4shorts
Elite Member
Cyril that white button is lighted and is used to activate the 3rd function valve that I use for the plow angling. Glad you liked the parking light. I don't drive off anymore with the brakes on
Soundguy
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If you think that is 100% true exactly as you typed it.. your EE teacher owes you some refunds.
soundguy
I stated it so those technically challenged could understand it.
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Capacitors in parallel with a voltmeter that is also in parallel with a car or tractor battery are useless.
Believe me, my teachers owe me nothing! I'm not the one who thinks you can dampen a meter when you have a 50 amp/hr battery sitting on it.
Looks like your teachers owe you a couple of bucks though!
Soundguy
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50ah batter seperated by some ? low slew rate 24awg antennas?
Filter capacitors have their place.. And you don't always install filter caps at the power source.. In many applications you install filter caps at the device that is getting interference.
Are you old enough to remember ignition style caps installed on the backs of radios for noise filtering? same concept, different application.
My teacher taught me to think outside the box. that not every application or situation we were going to encounter in the real world was going to have a page in the book to refer back to.
An analog meter won't need it.. but I believe someone mentioned a digital meter.. depending on how (cheap) the meter is.. it could very well benefit from a filter cap.
soundguy
Filter capacitors have their place.. And you don't always install filter caps at the power source.. In many applications you install filter caps at the device that is getting interference.
Are you old enough to remember ignition style caps installed on the backs of radios for noise filtering? same concept, different application.
My teacher taught me to think outside the box. that not every application or situation we were going to encounter in the real world was going to have a page in the book to refer back to.
An analog meter won't need it.. but I believe someone mentioned a digital meter.. depending on how (cheap) the meter is.. it could very well benefit from a filter cap.
soundguy
Soundguy
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- Location
- Central florida
- Tractor
- RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
I'd also like to point out that in an automotive or tractor application.. a voltmeter ( especially an analog one with an un marked scale with only a minimum and maximum voltage on either side of the scale, IE.. 8-18v is a very 'weak' tool in judging health of a charging system.
A center 0 ammter is a much better tool IMHO, and can tell you some important things that are hard to interpret from a analog volt meter.
For starters, a good hot battery on a very low electrical load is going to look very similar to a good hot battery being charged. IE.. 13.8 vs 14.4 is going to be hard to interpret on a cheap analog meter. Meaning your alt can die and as long as the load is low, the battery will carry the electrics.. slowly discharging.
On a diesel tractor with out headlamps running.. you might run around all day discharging your battery not knowing the alt is bad becaus ethe volt meter needle is 1 or 2 mm left of where it should be..
On a center 0 ammeter, as soon as there is no net positive current flow into the battery, the needle swings left of 0 showing discharge. if load is low as in above case, the needle will be hovering just barely left or even perhaps right at 0.. in either case.. 0 or left of 0 tells you you are experiencing NO CHARGE. Ideally you will experience a low positive NET charge, thus your center 0 ammeter would normally set just right of 0 except perhaps right after startup when you might see 10-60 a of charge depending on your charge system and battery condition.. etc. untill it tapers off to a small positive net charge into the battery.
Ammeters are also good at helping you determine if a battery has a bad cell. On a voltmeter, as long as the charge device keeps the charge rate high enough, the voltage will be correct.. but as soon as you turn her off you might have a 10v battery that won't start your engine.. but it still 'looked' good on the voltmeter gauge.
On an ammeter you could notice the higher than normal charge current.. IE.. 5-8a vs 3 and realize that you are charging higher than normal, then know that something is wrong.
I just had to run to ga to pick up a stranded family that had they had an ammeter rather than a volt meter their bad battery that was making the alternator charge it's guts out.. well.. they might have been able to stop and get it fixed vs breaking down on the interstate not near a shop. bat was bad.. made alt overcharge .. volt meter on dash looked good.. turned vehicle off.. bat was bat would not restart.. alternator was roasted.. so they had to repalce it AND a battery. An ammeter gauge might have saved them the cost of the alternator as it would have shown unusually high charge current. ( true story from sat night ).
soundguy
A center 0 ammter is a much better tool IMHO, and can tell you some important things that are hard to interpret from a analog volt meter.
For starters, a good hot battery on a very low electrical load is going to look very similar to a good hot battery being charged. IE.. 13.8 vs 14.4 is going to be hard to interpret on a cheap analog meter. Meaning your alt can die and as long as the load is low, the battery will carry the electrics.. slowly discharging.
On a diesel tractor with out headlamps running.. you might run around all day discharging your battery not knowing the alt is bad becaus ethe volt meter needle is 1 or 2 mm left of where it should be..
On a center 0 ammeter, as soon as there is no net positive current flow into the battery, the needle swings left of 0 showing discharge. if load is low as in above case, the needle will be hovering just barely left or even perhaps right at 0.. in either case.. 0 or left of 0 tells you you are experiencing NO CHARGE. Ideally you will experience a low positive NET charge, thus your center 0 ammeter would normally set just right of 0 except perhaps right after startup when you might see 10-60 a of charge depending on your charge system and battery condition.. etc. untill it tapers off to a small positive net charge into the battery.
Ammeters are also good at helping you determine if a battery has a bad cell. On a voltmeter, as long as the charge device keeps the charge rate high enough, the voltage will be correct.. but as soon as you turn her off you might have a 10v battery that won't start your engine.. but it still 'looked' good on the voltmeter gauge.
On an ammeter you could notice the higher than normal charge current.. IE.. 5-8a vs 3 and realize that you are charging higher than normal, then know that something is wrong.
I just had to run to ga to pick up a stranded family that had they had an ammeter rather than a volt meter their bad battery that was making the alternator charge it's guts out.. well.. they might have been able to stop and get it fixed vs breaking down on the interstate not near a shop. bat was bad.. made alt overcharge .. volt meter on dash looked good.. turned vehicle off.. bat was bat would not restart.. alternator was roasted.. so they had to repalce it AND a battery. An ammeter gauge might have saved them the cost of the alternator as it would have shown unusually high charge current. ( true story from sat night ).
soundguy
There's no need whatsoever for an RF capacitor on a voltmeter input, you'll never see it. Cheapness has nothing to do with it. Bypassing the power supply of a meter with a capacitor is completely different.
It's an entirely different application, you're talking about damping a voltmeter with a capacitor and ignition noise on an amplitude modulated radio.
A digital meter has several megaohms input impedance, a battery has milliohms. Damping is useless. You can't see a 100 microsecond or even a 1 millisecond RF spike on a digital or analog meter.
Thinking outside the box is one thing but let's try and stay within the laws of physics.
Rob
Huh?? Ok, I'm lost can you explain this statement?
