摘要 |
<p>A system for measuring electrical charge, comprising a capacitance detector (110) connected to a charge integrator (120) being an operational amplifier with a capacitance feedback (130), in which the input stage (121) of the charge integrator (120) comprises a pair of symmetrically connected JFET-type transistors (T1; T2), having gates connected to the input of the charge integrator (120).</p> |