SU712955A1 - Arrangement for converting digital code into time interval - Google Patents

Description

one

The invention relates to a pulse technique and can be applied in computing and control and measuring technology.

Devices are known for converting a code into a time interval 1, 2, comprising a clock pulse generator, a key, a pulse counter, and a decoder.

Such schemes have limited accuracy due to the finite time of the applied pulse counter.

The closest to the proposed technical entity is a device for converting a digital code in time interval 3, containing a pulse generator, the output of which is connected to the input of the time selector, the output of the latter is connected to the input of the counter, the receiving register, the outputs of which are connected to the inputs of the decipher, with the inputs of which are connected to the outputs of the counter, the output of the decoder is connected to the input of the generator, the input unit, the output of which is connected to the control input of the time selector, the generator pilo shaped voltage, reference voltage comparison element.

The purpose of the invention is to improve the accuracy of converting a code into a time interval without increasing the speed of an impulse counter.

This is achieved by the fact that, in the proposed device, the outputs of the input unit and the former are connected respectively to the first and second inputs of the sawtooth generator, the disconnecting input of which is connected to the output of the temporary selector, and the output of the sawtooth generator is connected to the input of the reference voltage comparison element.

FIG. 1 shows a functional block diagram of the proposed device for converting a digital code into a time interval; in fig. 2 is a timing diagram for explaining the operation of the device.

The device contains a pulse generator 1, the output of which is connected to one input of the temporary selector 2, the other input of which is connected to the output of the input unit 3, the generator 4 of the sawtooth voltage, one input of which is connected to the output of the input unit 3. The generator 4 of the sawtooth voltage is connected shaper 5 delayed pulse decoder 6, the inputs of which are connected to the outputs of the receiving register 7 and

the outputs of the counter 8. The output of the sawtooth generator 4 is connected to the comparison element 9, the second input of which is connected to the reference signal bus.

The device works as follows.

The conversion start signal is fed to the input unit 3, which outputs a signal to the time selector 2, allowing the passage of pulses from the pulse generator 1 to the counter 8. At the same time, the input unit 3 generates a signal that triggers the sawtooth generator 4. The first pulse, which appears at the output of the temporary selector 2, turns off the sawtooth generator 4; thus, the voltage to which the generator capacitor is charged is equal to

one

- Before

/ gi

. - J idt, o

where I is the capacitor charge current;

/ gi - the frequency of the pulse generator; Ab - phase mismatch of the pulse of the beginning of the transformation and the pulse generator.

Since the least significant bit of the counter 8 pulses is set to 1 before the conversion, the equality of the codes in the register and the counter occurs earlier on

time and driver 5 delayed / g

A pulse generates a signal that re-starts the sawtooth generator 4. As soon as the voltage on the capacitor of the generator reaches

1, these 7G g trigger the comparison element 9, at the output of which a pulse is formed; the delay value of the latter is determined by the initial positional code and looks like

/ c. (E2-1) + A8 + (A8),

I Lee /

where tgg:

/ gi

/ Accepts values in accordance with the position code written to the register.

From the above expression it follows that the conversion error, caused by the phase mismatch between the pulse of the start of the conversion and the pulse generator, is almost zero.

Claims (3)

1. USSR author's certificate number 321944, cl. N OZK 13/258, 1970. 2. Gitis E. I. Transformers of information for digital computers. M., "Energy, 1970, with. 211-212, 235. 3. USSR author's certificate for application number 1942597/21, cl. N OZK 13/20 dated 07.07.73. Cmapm-ufinyfbc 3aSepn (CfnHb / u pulse p 0 0 starting stroke