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BillA · 11-07-2003, 01:09 PM

am trying to assess the life expectancy of large (226W) TECs when controlled with PWM

googling I see 'controllers' with frequencies from 50 (!!) to 175kHz
with minimum frequencies described as 2k to 5kHz (to preclude/minimize thermal stressing)
- Motorola for example says 5kHz is a minimum

obviously filtering is required, but this is not my concern;
rather it is the life expectancy of a TEC at 'lower' cycling frequencies - say 500 cpm

anyone got some real info and or links ?
(please, no 'I think' kinda stuff)

11-07-2003, 01:09 PM	#1
BillA CoolingWorks Tech Guy Formerly "Unregistered" Join Date: Dec 2000 Location: Posts: 2,371.493,106 Posts: 4,440	PWM freq limit for TECs am trying to assess the life expectancy of large (226W) TECs when controlled with PWM googling I see 'controllers' with frequencies from 50 (!!) to 175kHz with minimum frequencies described as 2k to 5kHz (to preclude/minimize thermal stressing) - Motorola for example says 5kHz is a minimum obviously filtering is required, but this is not my concern; rather it is the life expectancy of a TEC at 'lower' cycling frequencies - say 500 cpm anyone got some real info and or links ? (please, no 'I think' kinda stuff)