TECHNIQUE MEASURING THERMAL RESISTANCE OF TWO-TERMINAL NETWORKS Russian patent published in 2003 - IPC

FIELD: measurement of thermal parameters of electric and radio elements. SUBSTANCE: technique measuring thermal resistance of two-terminal networks consists in that tested two-terminal network with trimming resistor connected in series is connected in parallel to reference two-terminal network with known thermal resistance R_T1 and with second trimming resistor connected in series. Short pulses of current of large relative pulse duration and fixed amplitude I₀ are fed. Resistance of trimming resistors is set such that equality of pulse powers dissipated by tested and reference two-terminal networks is realized and then constant heating current with value equal to amplitude of short pulses of current is supplied. Rated resistance of trimming resistors is chosen same and exceeding by factor of 10² rated active resistance of given type of two-terminal networks. Upon leveling of pulse powers but before supply of constant heating current amplitudes of voltages are measured across reference U₁₀ and tested U₂₀ two-terminal networks. After supply of constant heating current voltage is measured across reference U₁ and tested U₂ two-terminal networks under steady state and value of thermal resistance R_T2 of tested two-terminal network is found by formula where ΔU₁ = U₁-U₁₀ and R_T1 is thermal resistance of reference two-terminal network. EFFECT: widened class of tested two-terminal networks, possibility to obtain measurement result in the form of direct reading of measured value in chosen system of units. 3 dwg