Thermoelectric cooler (TEC) is a semiconductor device which is characterized by unique heat pump performance with high efficiency, compactness and durability. The unique ability of TECs to heat and cool, permits them to lower temperature of an object below ambient as well as to stabilize temperature of objects in widely varying ambient conditions.
Here we mention some application tips that can help in optimal use of TECs.
High quality DC current is smooth and constant with very low ripple or noise. The «quality» of the DC current is important.
Ripples of power supply reduces TEC performance in operation.
In a case of sinusoidal ripples the effect is the following concerning maximal TEC cooling capability ΔTmax:
ΔTmax - maximal specified delta T of a TEC at «smooth» DC current Im;
ΔT'max - maximal ΔT at rippled DC current with average Im;
Im - average current;
N - ripple amplitude in % to average current Im.
For rectangular ripples the ratio includes also dependence on ripple duty cycle:
Q- duty cycle ( Q=tON / t);
t - period of cycling;
tON - ON time.
RMT recommends limiting the ripple factor to less than 10% which will reduce the loss in performance to less than 1%.