A general thermodynamic formulation for the operation of a pulsed thermoelectric cooler is presented using the Gibbs law and simple energy balance method. An expression for the entropy flux (W/m(2) K) is expressed in terms of the key parameters employed for the thermoelectric operation. Following the classical temperature-entropy (T-s) methodology, which has all the virtues of energy flow identification, the processes along the p-n legs of thermoelectrics, contributing to both useful and dissipative losses, are clearly mapped for the transient operation. (c) 2005 Elsevier Ltd. All rights reserved.