Incremental vs Continuous Advance Timers

[Chetlaham]

Why did some manufacturers (like GE) use continuous advance timers, while others (like Whirlpool) had a preference for incremental advance?

One thing I never liked about incremental advance timers is that if you advance them some time after an increment is made but before another takes place (like when open a Power Clean or Durawashs DW in the middle of dry and turn the timer to the off position) the next increment at the start of the cycle is short in time (whirlpool always placed their cycle start detent on the fill and not a drain or advance increment like Maytag did).

But that aside, both timers were used on both Washer and DW by various brands.

 

[awooff]

Shortened fill

Learned something today then as never heard of incremental or continuous advanced timers but can see the difference.

The whirlpool quiet wash system (powerclean) timer for normal wash was always easy to cause an initial short fill unless you turned the timer to just before normal wash. (Was easy to hear the pump cavitate on a short fill)

Funny though heavy wash on the timer did not do this.

They washed so perfectly with high temp wash option that a shortened first fill probably made no difference.

 

[Chetlaham]

Until said fill is only 10 seconds. I'm surprised Whirlpool never got complaints about this, or considered it with people advancing the knobs during the dry cycle to "off" or to the next cycle after the door was left open.

However there are three down falls that I can think of when using a continuous advance timer:

1) Very high current draw items may need a drop on / drop off scheme whereby two contacts are used to cycle the load. This comes from the advancement of the timer being to slow to either break or make a high current contact fast enough. There is to much arcing during the slow ramp up.

2) It is more difficult to do short sub interval actions (1-15 seconds) like spray rinses.

3) You need long pauses between each step (ie going from agitate to spin) as to allow enough advancement to assure that all the right contacts have opened and all the right contacts have closed, all in the right sequence, prior to the next phase in the cycle.