How to mount capacitor to circuit board?

[scottyrocks]

I have had other engine work (heads) done a few months ago, but the capacitor is still doing its job perfectly.
_________________
“If you care for a thing long enough, it takes on a life of its own, doesn't it? Mending old things, preserving them, looking after them – on some level there's no rational grounds for it.”
– D. Tartt, 'The Goldfinch'

[MrGoodtunes]

The way condensers are made today, there's really nothing to guarantee a solid connection
between the actual capacitor and the can its in:

More on this is here:
http://nonlintec.com/sprite/cap_failure/

I found a good old style condenser on eBay. It has the roll'd top edge, forcing good can contact. Its top center terminal is a big solder blob, to which I solder'd an old style VW wire that has a bracket, grommet and cool rubber cap, making it sorta match my distributor.

[runamoc]

A capacitor's 'real' job is to block DC and allow AC to pass. The condenser is actually being used like a 'sponge' in an ignition system. The collapsing magnetic field around the coil, when the points open, creates thousands of volts on the primary coil (12v side) this is enough voltage to arc across the plug. During this interval the condenser discharges back through the primary winding producing an oscillation of the current flow in the primary circuit for the brief interval that is required for the primary circuit to return to a state of equilibrium. The condenser does not discharge until after the spark has occurred at the spark plug.

Contact pitting results from an out of balance condition in the system which causes the transfer of tungsten from one point to the other so that a tip builds up on one point and a pit on the other. The direction in which the tungsten is transferred gives an indication for correcting the situation. If the tungsten transfers from the negative to the positive point one or two corrections may be made. Increase the capacity of the condenser, shorten the condenser lead, separate high and low tension leads between the coil and distributor, move these leads closer to the engine block. If the transfer is from the positive to negative point, reduce condenser capacity, move low and high leads closer together and/or away from the engine block, or lengthen condenser lead.
_________________
Daily driver: '69 Baja owned 44 yrs - Plan B: '81 Rabbit Diesel LS Deluxe - Plan C: '72 Ghia
Yard Art: 2 Sandrails
Outback: '69 Ghia - '68,'69,'70,'72 Beetle - '84 Scirocco, GTI - Pair of '02 Golfs-
VW Wiring = It's just wires

[viiking]

You mean square waveform rather than sinusoidal?
_________________
1968 1500 RHD Lotus White Beetle since birth. In the hospital for major surgery
1966 Lancia Flavia Pininfarina Coupe - in the waiting room
Discharged: 1983 Vanagon, 1974 1800 Microbus,1968 Low Light,1968 Type 3

[PWB]

Something to ponder...
Having the condenser (capacitor) as close as possible, with minimum lead length to the points might be beneficial, or even essential to the longevity of the points.

From a design layout standpoint, it would be much more convenient to have the condenser wired up around the coil, or even built into the coil, but this configuration is not typically seen, and maybe for good reason?
Trace (wire lead) impedance becomes a more prevalent design requirement in electrical engineering when inductive loads, high frequency, and voltage come into play...

I wound try to keep the location of the condenser as close as possible to the points, but that's just me.

On a separate, but similar note, you hear a lot of guys complaining about how points aren't what they used be. Some claiming they only last a few hundred miles. I wonder how much of this issue is also a result of lousy condensers not sufficiently suppressing the arcs at the points?

[scottyrocks]

I will look into relocating my capacitor, then.
_________________
“If you care for a thing long enough, it takes on a life of its own, doesn't it? Mending old things, preserving them, looking after them – on some level there's no rational grounds for it.”
– D. Tartt, 'The Goldfinch'

[ashman40]

[scottyrocks]

The innards of the rebuilt distributor at the time I installed the capacitor are still in there doing their thing. However, over the course of that time the car was off the road more than it was on the road. So I really can't judge whether or not the excessive distance of the capacitor from the distributor has caused any excess wear to the points.

Now that the car is fully functional I don't want to find out.
_________________
“If you care for a thing long enough, it takes on a life of its own, doesn't it? Mending old things, preserving them, looking after them – on some level there's no rational grounds for it.”
– D. Tartt, 'The Goldfinch'

[bnam]

[scottyrocks]

Well, the last time I checked the points, they looked clean, so I guess I can leave the capacitor where it is. But I will keep an eye on it.
_________________
“If you care for a thing long enough, it takes on a life of its own, doesn't it? Mending old things, preserving them, looking after them – on some level there's no rational grounds for it.”
– D. Tartt, 'The Goldfinch'