SU883824A1 - Device for checking presence of ferro magnetic mass - Google Patents

Description

I

The invention relates to radio engineering and can be used in systems for monitoring the position of moving objects.

A device is known; THERE IS a control for the presence of ferromagnetic masses, which contains a video pulse transmitter, a receiver, an output unit, a coincidence unit, a blocking generator, the second output of which is connected to a coincidence circuit connected between the receiver and the output unit fij.

A disadvantage of the known device is the dependence of the response threshold on the magnitude of the release threshold, i.e. the dependence of the response gap on the magnitude of the return coefficient. With a decrease in the resistance of the positive feedback, the return coefficient decreases, as well as the size of the monitored gap, since the response threshold of the device due to the residual signal of the output amplifier shifts

towards large currents, i.e. separate adjustment of the threshold and release threshold is not possible, which reduces the reliability of the device.

The aim of the invention is to increase the reliability of the control.

The goal is achieved by the fact that the device for controlling the presence of ferromagnetic masses, containing

10 video impulse transmitter connected in series to the receiver, a matching unit, the second input of which is connected to a blocking generator connected to the input of the transmitter, and

Claims (1)

15, an offset source, wherein the output of the coincidence unit is connected to the output of the output unit, an inverter connected to the output unit is inputted, the input of which is bridged by a 2Q chain consisting of a first potentiometer and an offset source and the inverter output and the midpoint of the specified sequential chain the second potentiometer is turned on; The midpoints of both potentiometers are connected via diodes to the base of the receiver transistor. The drawing shows the functional diagram of the device for monitoring the presence of ferromagnetic masses. The device for controlling the presence of ferromagnetic masses consists of transmitter I, receiver 2 blocking generator 3, block A of coincidence, output unit 5, bias source 6, potentiometers 7 and 8, diodes 9 and 10, inverter. Transmitter 1 is a generator of 12 video pulses with transmitting antenna i3. The receiver consists of a receiving antenna 14 and an amplifier 15. The device operates as follows. Antennas 13 and 4 are located one above the other, for example, on the roof and on the ground generated along the track axis. Transmitter 1 generates (a pulsed magnetic field. Transmitter 1 is triggered by a blocking generator 3. In the absence of a controlled object in the receiving ante, the EMF induces an electromotive force (EMF) that amplifies the force1 (5el 5 and no match 4 unit arrives. 1a (5th input of block 4 coincidence arrives pulses from the blocking generator 3. From the output of block 4, the coincident current pulses are fed to the output block 5, which converts them into a DC voltage, which turns on inverter II, from potentiometer 8, connected between, the output of the inverter and the bias source, through the diode 10 is removed by the positon signal that is fed to the base of the input transistor of the transceiver 15. If a monitored object enters the space between the antennas, then the EMF induced in the receiving antenna 14 decreases, If the EMF value becomes less than the positive signal value When removed from the potentiometer 8 through the diode 10, the transistor of the amplifier 15 closes, which causes the signal from the inverter 11 to be removed. The amount of movement of the monitored object and the input space to the receiver triggered only by the magnitude of the positive signal, removed from the Potentiometer 8, since the reverse polarity is applied to diode 9 and the parallel feedback potentiometer 7, diode 9 does not work. When the signal is removed from the input of the inverter 11, the diode 9 is opened and the diode 10 is closed. A positive signal from the potentiometer 7 is supplied to the input of the transistor amplifier 15, and it is this positive signal that determines the value of the electromotive force when it comes out of the inter-antenna space at which the transistor of the amplifier 15 opens. Thus, the device has an independent adjustment of the response and release thresholds when the monitored object is moved to the inter-channel space, as well as changing the position of the antennas relative to each other. This makes it possible to increase the reliability of control over the occupancy of a section of the track, for example, with mine trolleys. . : Invention device for controlling the presence of ferromagnetic masses, comprising a transmitter-video pulses, a receiver connected in series, a coincidence unit, the second input of which is connected to a block 5-1ng generator / generator connected to the input of the transmitter, as well as an offset source, and the output of the block the coincidence is connected to the output of the output unit, characterized in that in order to increase the reliability of the control, an inverter is connected to the output unit, the input of which is bridged by a series chain consisting of Vågå potentiometer and bias source, and between the output of the inverter and the midpoint of said serial chain included a second potentiometer, the middle points of both potentiometers are connected via diodes to the base of the input transistor receiver. Sources of information, rintye taken into account in the examination of 1, USSR Copyright Certificate 374561, cl. G 01 R 3/86, 1974.