SU122943A1 - A way to convert voltage to a numerical equivalent and a converter for its implementation - Google Patents

Description

Methods are known for converting a voltage into a numerical equivalent based on comparing the voltage to be converted with a sawtooth voltage. In such methods, it is impossible to compensate for errors due to instability of the counting pulses and the shape and frequency of the sawtooth voltage. Therefore, such devices place particularly stringent requirements on the frequency of the counting pulses and on the frequency and shape of the sawtooth voltage.

Other known methods of converting voltage to a numerical equivalent, based on using an inversely transformed binary code to voltage in a mode of addition, require a significant amount of equipment and are complicated to set up.

The described method and apparatus for converting voltage to a numerical equivalent does not have the indicated disadvantages. The proposed method is based on a preliminary transformation of the input voltage into a time interval.

In the device being described, errors that may arise due to the mislady between the frequency of the counting impulses and the magnitude of the conversion interval are eliminated by the application of a counting circuit that performs a hard link between the counting pulse generator and the integrating circuit.

The drawing is a skeletal diagram of a voltage-to-digital converter.

It is known that if a core with a hysteresps loop close to a rectangular one is in a state of positive magnetization and an input voltage is applied to its winding 1 in the form of a pulse of duration, and then to winding 2 a fixed voltage U is sufficient 122943-2

duration, the time of transition of the core to the zero state naiiaYifriiieHHOCTH is determined by the expression

 .-Tv

,,,. ,

where wi and 112 are the number of turns of input 1 n corrective 2 windings, respectively. From the above relation it follows that if the winding I with the number of turns Wl of the magnetic core, set in advance to the state of zero magnetization, apply a rectangular pulse of fixed duration and unknown input voltage f / i, and after some time to the winding 2 with the number turns of Wz to give impulse of opposite polarity, having sufficient duration and exactly fixed voltage value, then the output winding 3 has a rectangular impulse, the duration of which is strictly onortsionalna magnitude of the input voltage.

The described method is used when working with the device shown in the drawing. At the initial moment of the device operation, the trigger 4 is in such a state that the valve 5 is closed and the key 6 is open.

A current flows through the winding 2 of the core, setting it to a state of zero magnetization. On arrival at the terminal 7 of the pulse of resolution, trigger 4 goes to the second stable equilibrium state by opening the creeper 5 and closing the key 6. Counter 8, through gate 5, from the generator 9 receives counting pulses. At some point in time t, the next cell of counter 5 will work, which through key 10 open on the side of trigger 4 will open key 11, Counter 8 will continue to work, and key 11 will remain open until point 2 when the last cell of counter 8 returns to its initial state.

Thus, during the calibration time interval (2- / 1, the key 11 remains open, and the input voltage b, from the clamp 12, acts on the input winding of the core).

Simultaneously with closing the key, trigger 4 returns to its initial state by closing valve 5 and key 10 and opening key 6. From clamp 13 through open key 6, the amplitude-calibrated voltage Uz acts on winding 2 of the core. An output pulse arises in the output winding 3, the duration of which is proportional to the input voltage f / i. This voltage reopens the valve 5, and the counting pulses from the generator 9 are again passed to the counter 8. Here the counter 8 operates in the mode of a pulse accumulator, the number of which is equivalent to the input voltage 6 / ,. Isolation nodes 14 and 15 serve to separate the pulses controlling the valve 5 from side 3 and trigger 4.

The advantage of the described device lies in the simplicity of the circuit, the absence of stringent requirements for the stability of the frequency of the counting pulses and the conversion interval. The device circuit is easily executable on semiconductor triodes.

Subject invention

Claims (2)

1. A method of converting a voltage into a numerical equivalent, characterized in that, in order to simplify the converter circuit and increase its reliability, the input voltage by integration is pre-converted into a time interval. 2. A converter for carrying out the method of claim 1, consisting of a counting pulse generator, a trigger, keys and an integrating device, characterized in that, in order to eliminate errors due to the possibility of a mismatch between the counting pulse frequency