TY - JOUR
AU - Kuz'menko, V.
AB - APPARATUS FOR MAGNETIC RECORDING OF LOW-FREQUENCY PROCESSES V. A. Kuz'menko UDC 615.471 : 612.014.423 A multivibrator with emitter capacitance incorporating three transistors was used for FM recording of signals with frequencies of 0-150 Hz. For an input signal of  10~A the coeffi- cient of depth of modulation is :~80%. Most methods previously described for FM recording on an ordinary tape recorder of signals con- taining low-frequency and steady components (EEG, EKG, blood pressure, respiration, and so on) are com- plex and cumbersome and require special power sources [2-4]. In the circuit proposed (Fig. 1), a multivibrator with collector-base connection was used as frequency modulator [5]. Any low-power low-frequency transistors of the P13, P15, and P16 type can be used in the circuit. The frequency of generation of the multivibrator is determined by the rate of recharging of the capacitor C. Rapid charging of the capacitor is effected through the triode T 1 as soon as it is triggered. The capacitor discharges through the triode T3, conductance of which depends on the magnitude of the input signal. During tuning the initial generator frequency is set at 3-4 kHz, corresponding to the mean frequency of the transmission band of the 
TI - Apparatus for magnetic recording of low-frequency processes
JF - Bulletin of Experimental Biology and Medicine
DO - 10.1007/BF00805213
DA - 2004-11-28
UR - https://www.deepdyve.com/lp/springer-journals/apparatus-for-magnetic-recording-of-low-frequency-processes-OvjL5EWL06
SP - 966
EP - 967
VL - 70
IS - 2
DP - DeepDyve
ER -