Recording level display circuit
Posted on Nov 10, 2015 5446
Provided only manual recording level control function, when the circuit is in the recording mode, the recording level as LM3915N was shown.
3-180 as shown in Figure 3-17 in the sound recording circuit by IC] RC network and related audio recording preamplifier circuit. In playback features common with (NOr) equalization circuit, with chromium (Cr02) and metal (Met) with three different tape playback equalization network network, controlled by switch o IC2a etc. playback voltage amplifier , to adapt the level of the input amplifier circuit requirements. IC2b and related network of recording equalization network, for ordinary tape and C12 composed by the R17RisCl1 low frequency compensation network, high-frequency compensation by R19, , Cl3, q4 composition o for chromium metal band and high frequency band, is only for compensation, C15 -, C16 and R2l composed of high-frequency compensation chrome band, C17.CIS Biao and high compensation network consisting of a metal band. RP3 potentiometer to manually adjust the recording level. High-frequency transformer T and VTi, VTz composed push-pull high frequency magnetic bias oscillation circuit, the oscillation frequency is 90kHz ;. The bias magnetic oscillator on the one hand to provide the erase erase head bias current, the other for audio recording heads for sound recording bias current. In order to ensure the stability of the oscillation frequency of the bias magnet, power supply magnetic bias oscillation circuit using an LC filter o Partial magnetic resonance oscillation circuit in common with the same set, chrome belt, metal band selector switch, to provide different oscillating current o