DEVICE FOR ORIENTATION OF THE BLIND Russian patent published in 1995 - IPC

FIELD: devices for orientation of the blind in space. SUBSTANCE: device comprises a transmitter, a receiver, electroacoustic converter and indicator and, additionally, is provided with a rectifier whose input is connected to the receiver output, first and second feedback channels whose inputs are connected to the rectifier output; the transmitter is made up in the form of successively-connected setting generator, power amplifier and transmitting antenna, said generator consisting of successively-connected first and second multivibrators; the input of the first multivibrator and the second input of the second multivibrator function, respectively, as the first and second inputs of the setting generator and, respectively, the first and second inputs of the transmitter; the receiver consists of successively- connected receiving antenna and amplifier with output stage encompassed by negative feedback across a capacitor, the first feedback channel is made up of successively-connected first low-frequency filter whose input functions as the input of the first feedback channel, DC amplifier, second low-frequency filter and first matching resistor whose output functions as the output of the first feedback channel while the second feedback channel is made in the form of a successively-connected threshold unit whose input serves as the input of the first feedback channel and of the second matching resistor whose output functions as the output of the second feedback channel. The electroacoustic converter is cut in between the receiver output and the indicator, the resistor is connected in parallel with the electroacoustic converter winding and the outputs of the first and second feedback channels are connected, respectively, to the second and first inputs of the transmitter. EFFECT: improved orientation of the blind in space. 4 dwg