Rally dash condenser. Is it necessary?
- Thread starter BAFRAID
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Mine didn't have one.... still doesn't..
I dont have one on my Bee
It is designed to regulate the 5V supply. They eliminate some of the fluctuation with the amp gauge with things like the blinkers, flashers and dash lights dimming with additional accessories being turned on. When bad or missing things usually work on the OK side, but if they short out you melt things.
BAFRAID
She’s looking like a Super Bee again!!
You were the one member I was speaking of. I ended up getting the other part you had mentioned. I may just go without the condenser.
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IMO...
The purpose of the condenser is to eliminate/reduce the effect (radio noise -- a popping noise) of the instrument panel's voltage regulator's internal contacts when they open-close to make the 5 volts to operate the temperature, oil pressure and fuel gauges. It has nothing to do with regulating the 5 volt supply. By using one of the RTEs electronic instrument panel voltage regulators, this condenser can be eliminated and your Mopar dash instruments will work great.
Cohtact information for:
Real Time Engineering. (RTE)
19352 Hilton Rd.
Springdale, AR 72764
http://www.rt-eng.com
Real Time Engineering
[email protected]
BOB RENTON
I think that is exactly what I was saying. The old style 5V supply is yes mechanical and the condenser smooths or regulates that supply for quieter and better operation of your electrical system. RTE's replacement has the condenser built in therefore you eliminate the external one. For all intents and purposes we are on the same track.
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To some regard yes...but not entirely....the RTE device uses a transistor and other internal electronic devices (zener reference diodes) to maintain the 5.0 volt DC output voltage supply to the instruments. In the design of origional Mopar mechanical instrument panel's voltage regulator, which was a thermal percent cycle timer, where it was on 5/12 of the time (out of 12/12 or 12 volts) to produce the necessary 5 volt output. The external capacitor, subject of this discussion, has nothing to do with regulating the output voltage produced, it's function is only to eliminate any radio noise from the cycling of the percent cycle timer's contacts. The RTE device has a internal feedback circuit and a referencing circuit, along with a circuit that protects the output voltage to kerp it from rising and potentiality damaging any instruments.
BOB RENTON
It does zero for gauge operation period. It is strictly a noise suppressor. Back in the day when these cars came without radio's there usually were none from the factory. When a over the counter radio package was ordered there was a sub package in the radio box kit. That kit had several suppressors with instructions. Common three locations, dash, alternator,and coil. Seems like they were mainly needed for AM radios where FM was less sensitive.
I have used the 12 to 5V transistor device on clusters before and retained the condenser for regulation. The main concern was to keep the output of the transistor to stay at 5V with the fluctuation of the input 12-13.2V. The original 5V supply as it's a timing device based on the input voltage allows for fluctuation of the output voltage.
From the Bible.
Interference Elimination
Three capacitors are used to suppress engine electrical
interference. The alternator is equipped with
an internal capacitor integral with the output stud. A
second capacitor is mounted on the back of the instrument
cluster with a self tapping screw (Figs. 2 through
4). The lead wire of this capacitor is connected to the
input terminal of the voltage limiter on all models.
A third capacitor is installed on the ignition coil
with the lead connected to the positive primary terminal
of the coil (Fig. 5). Radio resistance type wires
in the high tension circuit of the ignition system complete
the interference suppression.
If radio noises are evident, be sure the capacitor
lead wires are making good contact on their respective
terminals and are securely mounted. Faulty or
Interference Elimination
Three capacitors are used to suppress engine electrical
interference. The alternator is equipped with
an internal capacitor integral with the output stud. A
second capacitor is mounted on the back of the instrument
cluster with a self tapping screw (Figs. 2 through
4). The lead wire of this capacitor is connected to the
input terminal of the voltage limiter on all models.
A third capacitor is installed on the ignition coil
with the lead connected to the positive primary terminal
of the coil (Fig. 5). Radio resistance type wires
in the high tension circuit of the ignition system complete
the interference suppression.
If radio noises are evident, be sure the capacitor
lead wires are making good contact on their respective
terminals and are securely mounted. Faulty or
Yes, noise suppression is a side effect of what a capacitor, ie condenser does. It is also a regulator, and filter of which the last two are their primary purposes. I spent 31 years working for Ma Bell. My primary job was servicing their electronic and electro-mechanical switching systems. I am not qualified for a a lot of things but I do know what the purpose of a capacitor/condenser is in both AC and DC circuits.. Yes, they are used for radio noise suppression by there nature as your (Bible) quote indicates, but they are doing other things besides that. @RJRENTON has his ducks in a row on the subject and our differences are just communications problems. Thanks for your input.
Again the capacitor has no effect on the gauges. I want to make that clear. If it was intended to do that it would be on the output regulated side of the limiter which it is not. It is on the input side of the limiter. You can run with or without it and you will see no gauge operation differences.
BAFRAID
She’s looking like a Super Bee again!!
Dadsbee hooked me up with this site and I got one of these.
Yes, the condenser is on the input side of the limiter and it regulates the 12V there, which in turn keeps the 5V to the gauges steady. It doesn't directly affect the gauges other than if the 5V is steady the gauges will be more accurate. Also noise suppression in the 12V circuits is the positive side effect of regulation of the 12V in all 3 locations. These capacitors are also doing more than suppression in the circuits.
Yes their items are good, I'm familiar with their tachometer boards and calibration kits. I do my own solid state 5V regulators and retain the original condenser/capacitor on the clusters. Doing it my way costs less than a dollar and 15 minutes once the cluster is on the bench.
BAFRAID
She’s looking like a Super Bee again!!
That’s awesome.
Also the old copper plug wires where a cause of static on the am radio station's. Many of us put the condenser on the radio it's self to filter out that static.
They also give better gas mileage and improve the ride.
steve817
Well-Known Member
Great information from the previous comments. I always like to keep everything original as possible in my restoration work, therefore, even when I use the AMAZING RTE voltage limiters, I always reinstall the suppressor and the fish tape. It just looks complete and better. I know, not everyone will agree, however, that is just the way my customers prefer it.
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