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Old 02-14-2005, 08:51 PM   #16
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in no way do any damage as long as the speedo is off....


the reason we say the speedo should be off, is you dont want to charge your car when it is on...


Ive been racing 17 years.. ive run every speedo from sport to pro level.. i have always before every single race..(hundreds of them) I peak the battery while everything is conected.... i have never had one be damaged, nor have i ever heard or seen anyone else damage one this way....

i have never heard of any speedo control company, saying this will damage it either...

newracer
thats your preference not to do it,,,, but in all honesty your not damaging anything.. the switch stops all power from entering the speedo.....Why would a pro level racer, risk damage right before a run, at a major event??? WHY??? because it cant hurt the speedo..
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Old 02-14-2005, 09:01 PM   #17
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I also have never seen it hurt anything but the reply that the switch stops all current from entering the esc is false. The switch is not in line on the power wires. All the switch does is shut off power to the rx and maybe a small portion of the esc but not the main power comming in or out. Think about it, you think that little switch with those little wires can handle the amp draw that we run through our cars? All I am saying is that there is potential, granted probably low, but the potential is there to damage the esc. What do you think would happen if you accidentally shorted the + and - together while the battery and esc were connected? Not only would you probably damage your batteries but also the esc.
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Old 02-14-2005, 09:44 PM   #18
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Quote:
[i]What do you think would happen if you accidentally shorted the + and - together while the battery and esc were connected? Not only would you probably damage your batteries but also the esc. [/B]
but thats like saying theres the potential to wire the neg and pos wires the wrong way to side of a batery pack.
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Old 02-14-2005, 09:59 PM   #19
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Quote:
Originally posted by newracer
I also have never seen it hurt anything but the reply that the switch stops all current from entering the esc is false. The switch is not in line on the power wires. All the switch does is shut off power to the rx and maybe a small portion of the esc but not the main power comming in or out. Think about it, you think that little switch with those little wires can handle the amp draw that we run through our cars? All I am saying is that there is potential, granted probably low, but the potential is there to damage the esc. What do you think would happen if you accidentally shorted the + and - together while the battery and esc were connected? Not only would you probably damage your batteries but also the esc.

WITH NO POWER TO THE FETS, THE CURRENT "GATES" ARE NOT OPEN !

THERE IS NO "BACKFEED" CURRENT.

SPEEDOS ARE ELECTONICALLY NOT DESIGNED TO ALLOW CURRENT FLOW WHEN INACTIVE.

AGAIN...FETS WITHOUT POWER ARE ELECTRICALLY INCAPABLE OF ALLOWING CURRENT FLOW.

Get a FET from Radioshack. Turn your multimeter to Ohm continuity test. Place + and _ leads on the FETS two legs. Zero current flow...not even high resistance...simply ZERO current flow.

A FET requires it's target design voltage delivered from the proper circuit before it is able to operate.





PURE



PLAIN



SIMPLE.
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Old 02-14-2005, 10:28 PM   #20
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Quote:
Originally posted by Soviet
WITH NO POWER TO THE FETS, THE CURRENT "GATES" ARE NOT OPEN !

THERE IS NO "BACKFEED" CURRENT.

SPEEDOS ARE ELECTONICALLY NOT DESIGNED TO ALLOW CURRENT FLOW WHEN INACTIVE.

AGAIN...FETS WITHOUT POWER ARE ELECTRICALLY INCAPABLE OF ALLOWING CURRENT FLOW.

Get a FET from Radioshack. Turn your multimeter to Ohm continuity test. Place + and _ leads on the FETS two legs. Zero current flow...not even high resistance...simply ZERO current flow.

A FET requires it's target design voltage delivered from the proper circuit before it is able to operate.

PURE

PLAIN

SIMPLE.
I understand, no power is going through the FETs but there is still power to portions of the board and current flow, very little but it is there. Ever left a charged battery connected to the esc, it will be drained in a day or two.

My point is that unless at least one power wire is disconnected there is still over 9 volts getting to portions of the esc. Simply switching off the esc will not totally protect it.
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Old 02-14-2005, 10:32 PM   #21
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WELL if your worried about burning your speedo while charging and everything is connected . Touch your speedo and youll find no heat built up .. As everyone has stated it is a safe way to peak your pak before a run ,, I also have been racing for many years and have always done it that way ....
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Old 02-14-2005, 10:44 PM   #22
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90% of the speedos on the market are rated for 4-10 cells..

10 cells X 1.2 volts =12 volts.. i doubt the 9 volts you are refering to will do any damage..

i have a buggy, that i bash around with occasionally.. i rarely if ever disconect the battery... i have left it in the car charged, and never had it drained from sitting.. the pack itself will drop to a lower voltage from sitting... but the speed control doesnt eat the power...

a guy that i use to race with, works for novak.. ill get in touch with him, and put and end to your theory....i will post what he has to say
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Old 02-14-2005, 11:29 PM   #23
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Quote:
Originally posted by Soviet
WITH NO POWER TO THE FETS, THE CURRENT "GATES" ARE NOT OPEN !

THERE IS NO "BACKFEED" CURRENT.

SPEEDOS ARE ELECTONICALLY NOT DESIGNED TO ALLOW CURRENT FLOW WHEN INACTIVE.

AGAIN...FETS WITHOUT POWER ARE ELECTRICALLY INCAPABLE OF ALLOWING CURRENT FLOW.

Get a FET from Radioshack. Turn your multimeter to Ohm continuity test. Place + and _ leads on the FETS two legs. Zero current flow...not even high resistance...simply ZERO current flow.

A FET requires it's target design voltage delivered from the proper circuit before it is able to operate.





PURE



PLAIN



SIMPLE.
Look..I used to be an avionics technician in the Marine Corps.

Electronics are all the same when you get down to basics.

The speedo doesn't even "SEE" the battery when it's switched off.

PERFORM THE FOLLOWING TEST TO SEE THAT I'M CORRECT:

1. Using a digital voltmeter, place the pos test on the pos batt terminal. Now place the neg test on the motor neg.

2. Repeat, except with the radio and speedo on. Again...zero voltage.

3. Repeat with a good burst of trigger, you will now see the exact output of speedo.

4. Now shut everything down and connect a charger and charge batts. Repeat test one. Again...ZERO VOLTAGE.
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Last edited by Soviet; 02-14-2005 at 11:39 PM.
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Old 02-15-2005, 12:08 AM   #24
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Does anyone know what's the effect of charging that big ol' cap that's soldered to your ESC?

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Old 02-15-2005, 12:28 AM   #25
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a tad off topic, but if you dont mind i will explain

Capacitors are designed to act as a sort of battery, but they do not hold their charge for extended periods of time. A capacitor wired to the battery leads (from your ESC) basically smooth's out the acceleration of your car. When you punch on the throttle of an electric r/c car, the voltage coming from the battery drops for a fraction of a second. a small capacitor (1000 micro farads) smooth's out this voltage drop. you might find it is not noticable. a bigger capacitor has the possibility to give your car more "punch". When you let off the throttle, the power from the battery charges up the capacitor, then when you pull the trigger/push the stick, all the power from the capacitor will be released.

I am sorry if there are any errors in this, i have this knowledge from reading off the internet.

(p.s. i also heard that a capacitor can lower the temperature of your ESC when running!?!?)
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Old 02-15-2005, 01:56 AM   #26
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Quote:
Originally posted by adamkerrnz
a tad off topic, but if you dont mind i will explain

Capacitors are designed to act as a sort of battery, but they do not hold their charge for extended periods of time. A capacitor wired to the battery leads (from your ESC) basically smooth's out the acceleration of your car. When you punch on the throttle of an electric r/c car, the voltage coming from the battery drops for a fraction of a second. a small capacitor (1000 micro farads) smooth's out this voltage drop. you might find it is not noticable. a bigger capacitor has the possibility to give your car more "punch". When you let off the throttle, the power from the battery charges up the capacitor, then when you pull the trigger/push the stick, all the power from the capacitor will be released.

I am sorry if there are any errors in this, i have this knowledge from reading off the internet.

(p.s. i also heard that a capacitor can lower the temperature of your ESC when running!?!?)
You are 99.98% correct sir! The remaining .02% doesn't matter in R/C applications.
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Old 02-15-2005, 04:50 PM   #27
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Default Re power caps

Read this, intresting .

capacitors and what effect they have
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Old 02-15-2005, 05:41 PM   #28
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Quote:
Originally posted by newracer
I also have never seen it hurt anything but the reply that the switch stops all current from entering the esc is false. The switch is not in line on the power wires. All the switch does is shut off power to the rx and maybe a small portion of the esc but not the main power comming in or out. Think about it, you think that little switch with those little wires can handle the amp draw that we run through our cars? All I am saying is that there is potential, granted probably low, but the potential is there to damage the esc. What do you think would happen if you accidentally shorted the + and - together while the battery and esc were connected? Not only would you probably damage your batteries but also the esc.

dont walk outside you might get hit by a
meteorite!

think of the speedo as a relay. Like the ones in a car. There is always 12 vlts at the relay but when the switch is turned on an arm moves inside that completes a circut and powers the load.
When we say a speedo is like a gate the internals are basically a highly techno relay.

Does your car catch fire sitting there? No righht!. Everything comes to life when you insert the keys!
Same thing as the lights in your house theres constant power there till you hit the light switch that completes the circut!

Hope you under stand now! If not then do what your doing and keep believing your right!
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Old 02-16-2005, 04:25 PM   #29
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Well Novak advises to error on the side of caution for the same reason I stated.

Quote:
Hello,

Usually there is no problem, but if anything goes wrong with the charger or one of the leads is shorted for any reason, you'll damage everything. We often repeak our batteries when connected to the ESC, but you should avoid long term charging if you can.

Please let me know if you have any further questions, we are glad to help. Complete Product return, service, and pricing information can be found in the Customer Service Section of our website. Instruction manuals can be found in the Download Section of the website as well. All links are listed below.

Thank you,
Charlie Suangka
Novak Electronics
17032 Armstrong Ave
Irvine CA 92614
www.teamnovak.com
phone 949-833-8873
fax 949-833-1631
[email protected]
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Old 02-16-2005, 05:18 PM   #30
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Default Re: Novak's responce

Quote:
Originally posted by newracer
Well Novak advises to error on the side of caution for the same reason I stated.
NO...for a different reason.

Novak said that if anything went wrong with the CHARGER or if the leads were SHORTED.

Look...even with the switch off, if the speedo connection gets hit with a momentary voltage spike from a blowing charger on the order of 100,000 volts, of course there could be damage...because the FETS gate even when off couldn't repel such a massive spike due to internal arcing.

Do you even know what arcing is?

If you do then you'd realize that that is all Novak is cautioning against when charging with all the gear hooked up.



Look...for EVERYONE else but you, charging with the speedo hooked up is a-ok.
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