IAC1: Test signal alters the transistor’s voltage, changing its capacitance and affecting the measurement
WHY CONVENTIONAL POWER SUPPLIES CANNOT BE USED FOR INDUCTOR TESTING
GENERAL-PURPOSE POWER SUPPLIES COMPROMISE ACCURACY AND MAKE MEASUREMENTS IMPOSSIBLE
CONVENTIONAL (GENERAL-PURPOSE) POWER SUPPLY
VOLTECH DC1000A DC BIAS CURRENT SOURCE
| Problems with Conventional (General-Purpose) Power Supplies | DC1000A DC Bias Current Source Solution |
|---|---|
| LCR test signal goes into the output capacitor, not the inductor | No output capacitor - LCR test signal passes directly through the inductor |
| Test current bypasses the inductor | Measures actual inductance |
| Misleading measurement results | Ensures consistent, high-precision test results |
| Hard to detect measurement errors | Purpose-built for DC bias testing with any LCR meter |
MINIMIZING AC ERROR CURRENTS
IAC2: The LCR meter’s AC signal leaks into the DC bias supply via the transistor’s imperfect load line, causing error currents that varies with DC bias
IAC3: Capacitance between the DC path and ground diverts current from the LCR measurement
HOW DC1000A SOLVES ERROR CURRENTS
1) Sense Winding Detects Test Signal
2) A high gain control loop injects AC Signal across the inductor
3) Drives the AC voltage across the inductor towards zero
RESULT: ERROR CURRENT REDUCED BY UP TO 100×
