PURPOSE: To obtain stable and definite erasing effect by generating an invariably- constant erasing current by disconnecting an erasing current generating circuit from a recording bias current generating circuit.
CONSTITUTION: Coil L1 has the same inductance as erasing head H3 and its across output is supplied to erasing current generating circuit 2. Although constituting an oscillator close enough to Colpitts one using transformer T2 identical to oscillation transformer T1 of recording bias current generating circuit 1, circuit will not oscillate by itself without capacitor C10 and supplying an input from coil L1 to transistor Q3 via capacitor C10 develops an erasing voltage at the secondary side of transformer T2, so that this voltage should be the highest by selecting the value of resonance capacitor C15. As a result, the erasing current is equal in frequency to the bias current to cause no beat and the erasing current depends upon the inductance of head H3 and the power voltage of circuit 2, so that even if the input to transistor Q3 changes, the current will be held constant.
| JPH11110710 | ERASING HEAD DRIVING CIRCUIT |
| JPH0693290 | [Title of Invention] Rotating Magnetic Head Device |
SANBE TOORU
HIGUCHI SHIGEMITSU
YAMADA MASAMICHI
ARAI TAKAO
