voltmeter

[howel14]

mga magkano po ba magagastos kung papakabit ng voltmeter sa auto?

saw this thread kc sa isang forum ---

Voltmeter Install

Alternator failure is the common denominator among car owners, it strikes suddenly and leaves you wondering how to get home. Cold and rainy weather also does funny things to the car sometimes. It happened to me as the car simply died in the middle of the road when I let of the throttle. Prior to that, the radio was already crackling on and off and the lights were dimming. Well now with a voltmeter I can precisely monitor my electrical system's health, normal voltage would be 13.8- 14.0 volts, if that ever drops to 11.5, something is definitely wrong.

1.

Remove the seats because its a lot easier to remove them than to work around them. Remove the center console.

2.

I've cut out the cigarette lighter, it has four wires, 2 are for the orange kight ring aournd it and the other 2 are for the actual lighter.

3.

I got an Autogauge Voltmeter, Its made in Taiwan but looks good, it works and has a warning light if ever voltage drops below 11.5v.

thanks

[wildthing]

merun akong plano na ganyan - i think i have all the needed materials na lying around my box of "goodies" (junks actually) - pero i haven't started it yet.

i bought an analogue volt meter na pang 20volts max ang read-out and i plan to mount it sa cigarette lighter outlet...so i just have to "attach" the voltmeter dun sa cigaretter lighter plug (donor was a sirang celphone charger). So if i want to monitor the voltage of the car, I'll simply plug the thing dun sa cigarette lighter outlet.

pretty basic wiring positive to positive pole of the voltmeter and the negative sa ground ng car.

[wildthing]

voltmeter was bought from an electronic store (lots of variants available)...cost P65

[raine]

merun akong plano na ganyan - i think i have all the needed materials na lying around my box of "goodies" (junks actually) - pero i haven't started it yet.

i bought an analogue volt meter na pang 20volts max ang read-out and i plan to mount it sa cigarette lighter outlet...so i just have to "attach" the voltmeter dun sa cigaretter lighter plug (donor was a sirang celphone charger). So if i want to monitor the voltage of the car, I'll simply plug the thing dun sa cigarette lighter outlet.

pretty basic wiring positive to positive pole of the voltmeter and the negative sa ground ng car.

good idea pwede mo pang alisin kung ayaw mo na. at wala ng masyadong gagawin like cutting sa panels ang wiring.

[Cult Zero]

merun akong plano na ganyan - i think i have all the needed materials na lying around my box of "goodies" (junks actually) - pero i haven't started it yet.

i bought an analogue volt meter na pang 20volts max ang read-out and i plan to mount it sa cigarette lighter outlet...so i just have to "attach" the voltmeter dun sa cigaretter lighter plug (donor was a sirang celphone charger). So if i want to monitor the voltage of the car, I'll simply plug the thing dun sa cigarette lighter outlet.

pretty basic wiring positive to positive pole of the voltmeter and the negative sa ground ng car.

very simple and creative solution ... para kang si mcgyver bro

[howel14]

thanks mga bro!

mukhang ok na din ung P65.- na analog VM,
may nkita din ako sa isang forum .. may mga digital na din daw, around P1,200.- ang cost nya, available sa CONCORDE

thanks mga paps!!

[HIFI]

The best way to monitor the health of your electrical system is a current meter - amperes meter.

This measures the current consumption minus the charging state of the battery. If fact, you'll see kung gaano kalakas mag drain ng battery power ng mga busina.

I remember my dad use to put these on our jeeps. "Roxs" ang brand, at may - 0 +.

A voltmeter will of course to the job too...in a way, and it's easier to install. However, in electrical terms, it's crude. Battery condition lang ang monitor nito, not the alternator.

You can have both...voltmeter and ampere meter, para mas maganda.

My 2 centavos lang.

[rogie]

merun akong plano na ganyan - i think i have all the needed materials na lying around my box of "goodies" (junks actually) - pero i haven't started it yet.

i bought an analogue volt meter na pang 20volts max ang read-out and i plan to mount it sa cigarette lighter outlet...so i just have to "attach" the voltmeter dun sa cigaretter lighter plug (donor was a sirang celphone charger). So if i want to monitor the voltage of the car, I'll simply plug the thing dun sa cigarette lighter outlet.

pretty basic wiring positive to positive pole of the voltmeter and the negative sa ground ng car.

nice idea po sir try ko din toh... actually im looking for a voltage meter na salpak lang sa cigarette lighter outlet para pwede tanggalin... eto po yung pics

[wildthing]

rogie...it would be something like that...but mine wold be a bit more crude (kasi analogue vm)...btw yung vm na nakuha ko ay ammeter din...I just have to wire it properly (i have yet to put my brains how - vm yata pag parallel at ammeter naman kung series ang connection)...

plan ko lalagyan ko lang ng switch to make it vm or am.

[StraightSix]

rogie...it would be something like that...but mine wold be a bit more crude (kasi analogue vm)...btw yung vm na nakuha ko ay ammeter din...I just have to wire it properly (i have yet to put my brains how - vm yata pag parallel at ammeter naman kung series ang connection)...

plan ko lalagyan ko lang ng switch to make it vm or am.

Yes, you can use an ammeter as a voltmeter. The best range to use (to use as a voltmeter) would be low-range ammeters (ex: µAmp range) - I'll explain the reason later.

You can connect the ammeter the same way as a voltmeter, but with one tiny detail ... that is to insert a precision resistor in series to the meter. 'Di ko mai-drawing, so ganito lang: (+) battery to (+) ammeter, (-) ammeter to resistor end, opposite resistor end to (-) battery. Actually you can insert the resistor on the other side of the meter, series naman siya.

Now, according to Ohm's law ...
voltage = current * resistance
V = I*R

Pick a fullscale voltage mark, say you want 16v to be the max reading of your ammeter. If your ammeter's dial range is 0-100 µAmp, then you'll know what resistor to use ...
R = V/I
R = 16v / 100 µA
R = 160kΩ

To know at what µA mark the other voltage readings would be, use Ohm's law again. Like at 14volts, the ammeter reading would be ...
I = E/R
I = 14v / 160kΩ
I = 87.5µA
And so on for the other voltage readings ...

Now if you're going to use a high-current ammeter, medyo mahihirapan kang maghanap ng high-wattage[SIZE=4][SIZE=2] precision resistor. But if you are to use a [SIZE=4][SIZE=2]µ-ammeter as a voltmeter and an ammeter, too, bitin naman yung range ng ammeter because of the large current involved. [/SIZE][/SIZE][/SIZE][/SIZE]

Ooops ... sumobra pagka-OT

[SIZE=4][SIZE=2][SIZE=4][SIZE=2]HTH[/SIZE]
[/SIZE][/SIZE][/SIZE]

[Cult Zero]

straightsix, EE or ECE ka ba? Ayos sa explanation magaling ka pa sa prof ko sa electrical circuits nung college hehehe

[wildthing]

hindi naman OT. thanks sa info

[CVT]

What StraightSix was trying to illustrate is how to use an Ammeter as a Voltmeter.

I guess what wildthing wants is how to use his multimeter, in this case a Voltmeter and an Ammeter side by side.

The connection for a Voltmeter is pretty much straightforward. It's parallel to a battery load. A cigarette lighter interface is an example.

However, for an Ammeter, it needs to be in series with the source. So, if you want to measure the charging current of the alternator, the connection needs to be in series with the alternator and(to) the battery. Pretty messy wiring.... A current clamp should be in the off'ing but not a feature of the regular multimeter...

3404:surfing:

[meledson]

Yes, you can use an ammeter as a voltmeter. The best range to use (to use as a voltmeter) would be low-range ammeters (ex: µAmp range) - I'll explain the reason later.

You can connect the ammeter the same way as a voltmeter, but with one tiny detail ... that is to insert a precision resistor in series to the meter. 'Di ko mai-drawing, so ganito lang: (+) battery to (+) ammeter, (-) ammeter to resistor end, opposite resistor end to (-) battery. Actually you can insert the resistor on the other side of the meter, series naman siya.

Now, according to Ohm's law ...
voltage = current * resistance
V = I*R

Pick a fullscale voltage mark, say you want 16v to be the max reading of your ammeter. If your ammeter's dial range is 0-100 µAmp, then you'll know what resistor to use ...
R = V/I
R = 16v / 100 µA
R = 160kΩ

To know at what µA mark the other voltage readings would be, use Ohm's law again. Like at 14volts, the ammeter reading would be ...
I = E/R
I = 14v / 160kΩ
I = 87.5µA
And so on for the other voltage readings ...

Now if you're going to use a high-current ammeter, medyo mahihirapan kang maghanap ng high-wattage[SIZE=4][SIZE=2] precision resistor. But if you are to use a [SIZE=4][SIZE=2]µ-ammeter as a voltmeter and an ammeter, too, bitin naman yung range ng ammeter because of the large current involved. [/SIZE][/SIZE][/SIZE][/SIZE]

Ooops ... sumobra pagka-OT

[SIZE=4][SIZE=2][SIZE=4][SIZE=2]HTH[/SIZE]
[/SIZE][/SIZE][/SIZE]

Ammeters are actually voltmeters but magkaiba ang connection nila.

Voltmeters use voltage dividers (resistor in series). Low voltage kasi ang coil (analog) so mag series ka ng mataas na resistor. The higher resistance, the higher the voltage that can be measured. Ideal Voltmeters have infinite resistance. Para di maka affect the lugar na nag measure ka ng load.

Ammeters have shunt resistors ( resistor in parallel to the coil). Ammeters measure the voltage across the low resistance. The lower the resistance, the higher the current that can be measured. Ideal Ammeters have zero resistance, para walang effect the circuit.

Let us say gusto mo na i-measure the current na lumalabas o pumapasok sa battery, you will place the ammeter in series with the battery. (What would happen if you have a 160KOhm resistor in series with the battery?) Old school automotive analog meters measure frpm -60 to +60, sa iba -30 to +30 lang.

BUT, you do not actually insert an ammeter (for automotive applications) in series. you use a current transformer. a current transformer is a coil that you place around the wire you want to measure the current. This is the principle used by hand held clamp meters.

In my opinion, it will be much easier to monitor the voltage then the car is running, turned off and cranking the engine. Voltage no load (patay lahat pati makina) sould be at least 13.8 volts and better. Cranking the engine consumes a lot of current, the voltage should not go to less than 11 volts (I am not sure on this) When the car is running, the voltage should be higher than voltage no load. This signifies that it is being charged.

Sorry, haba na e..

[howel14]

thanks sa mga cool at mga techy na reply mga peeps! ngayon ko na-a-appreciate ung mga tinuro ng prof ko hehe, mabuhay ang mga EE/ECE at lahat ng eng'g//

salamat sa mga ganitong forums dahil madami tayong natututunan

anyway, knya ko ginawa tong forum n to e dahil nagloko ung alternator ko, bale nagiilaw sa dashboard ung batt indicator tapos nangangamoy sunog ung alternator, may mga naka-experience nb sa inyo nito?

sabi nung taxi driver na nasakyan ko, malamang daw e nabasa ung alternator tpos naka-ON ung aircon ko, mukhang tama nga dahil malakas ung ulan dito sa Makati last Wednsday tpos e dala ko ung auto,

bukas ko pa lang kc ipapa-check ung alternator ko, bukas lang kc free dahil weekend, sabi ng driver e possible na sunog daw ung carbon, palitan ko lang daw ito, oki na, may mga naka-experience po b sa inyo?

salamat at mabuhay ang tsikoters!

btw, my ride nga pala e 95 na corolla

[SpiritBeing]

sa mga electronic hobbyists baka makatulong tong simple car voltmeter led display http://homepage.sunrise.ch/mysunrise.../voltmeter.htm