SU1228283A1 - Current-to-frequency converter - Google Patents

Abstract

The invention can be used in automation devices, accurate magnetic recording with wideband frequency modulation. The purpose of the invention is to expand the frequency range of the conversion to the low frequency range. The device contains an integrating capacitor 1, a threshold element 6, a source 2 (negative) voltage, a switch 3, a resistor 4, a metering device 7, including a source of 8 (positive) voltage, a switch 9 and 10, a reference voltage source 11, which fixes a diode 12, separation diodes 14 and 15 and metering capacitor 13. Switching on the one-shot 15 provides full transfer of the dose to discharge the integrating capacitor 1. At the same time, the start-up delay of the one-shot does not affect the stability of the conversion. 2 Il. § (L N3 Is3 CX5 ND 00 CO

Description

The invention relates to electrical measuring equipment, and can be used in automatic devices and devices for accurate magnetic recording with frequency band modulation about

The purpose of the invention is to extend the conversion range to the low frequency range by switching on a single vibrator, which provides a complete transfer of the dose to discharge the integrated capacitor. In this case, the launch delay of the single vibrator does not affect the stability of the conversion.

Fig oi shows the functional diagram of the converter; in figs, timing charts.

The converter contains an integrating capacitor I $ source 2 (negative) voltage, a key res1-1stor 4, a one-shot 5, a threshold element 6, a metering device

7 ;, which includes the source

3 (sheet-gtel) voltage; the keys 9 and W are the source 11 of the reference voltage, firmfixing the bottom 12, the metering capacitor 13, separating the diodes 14 and 15.

The first plate of the integrating capacitor 1 is connected to the input bus, the first input of the threshold element 6 and the first output of the metering device 7, the second plate to the common bus of the device and the second output of the metering device. The output of the threshold element 6 is connected to the output terminal and to the input of the one-oscillator b, the output of which is connected to the control input of the switch 3. The source 2 of the negative voltage switch 3 and the resistor 4 are connected in series. In addition, the output of resistor 4 is connected: key 3 ,, is connected to the second input of the threshold element 6 and the SECOND output is connected to the common device bus,

The amplitude-normalized time diagrams explaining the operation of converter 5 are shown in FIG. 2. where voltage 16 is indicated on the integrated capacitor; voltage 17 on the grieved entrance of the threshold element; voltage 18 at the output of the threshold element and the output of the one-shot.

The device works in the following way ...

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When the voltage on the integrating capacitor 1 is below the operation level of the threshold element 6, the dosing capacitor 13 is charged through a short switch 9 and a separating diode 15 to a voltage disconnected by a dimming 1M diode 12. At the same time the switch 10 the metering device 7 is open and the integrator / capacitor 1 is charged by the input current.

When the voltage on the integrating capacitor 1 reaches the triggering level of the threshold element 6, the latter produces a pulse for the M51 key 10 of the metering device 7 and the disconnecting key 9, and the metering conepsor 13 is recharged via the closed key 10; The separator is a diode 14 and and 1 is an integrated capacitor 1. As a result, the redistribution of the capacitors' charge, and the integrating capacitor p € occurs; the metered charge is given. The voltage across the integrating (the capacitor i is lowered below the threshold element 6, the output voltage is visible; at the output of the threshold element 6, when it is triggered, it also launches the one-shot 5, which also produces ffly; cc ,, a hidden key 3, through which the second input of the threshold element 6 is fed by the voltage from the source 2 of the negative voltage.

For the time of one-shot pulse, the 5th threshold is the average of the threshold-of-element element 6, t, e. Compression 17 is pa of its second input. It shifts to the area of negative voltages. The duration of the impulse of the one-shot 5 can be tzibrana.K5 that at any frequency of operation the dose 6yj: i; eT is almost completely transmitted to the integrating capacitor.

The pulse duration of the one-shot 5, and therefore its stability, does not determine the downturn transmitted by the integrating capacitor, and therefore does not determine the stability and linearity of the drive in contrast to the converters with a single-shot metering device. Other inclusions of the one-vibrator are possible, at which the duration of its H pulse (2 influences the stability and linearity of the converter; So, for example, a single-nibrator can be switched on by the output of the electric elec

five

Step 6 and the input of the metering device 7. But in this case, the launch delay of the one-shot (the value is unstable, since it is associated with the process of resorption of the charge of the transistor in its composition) will be one of the values determining the frequency of the converter.

Claims (1)

Invention Formula A current-to-frequency converter containing an integrating capacitor, the first plate of which is connected to the input bus of the device and the first input of the threshold element, the output of which is connected to the output bus of the device and the input of the metering device  ABOUT 15 28283 The first output is connected to the first plate of the integrating capacitor, and the second output is connected to the second plate of the integrating capacitor 5 and a common bus device, characterized in that, in order to expand the frequency conversion range, a voltage source, a switch, a resistor are entered into it. and a one-shot, the input of which is connected to the output of the threshold element, the output of the one-shot is connected to. the control input of the key, and the second input of the threshold element through the switch is connected to the voltage source and through a resistor to the common bus of the device. Editor T. Mitejko Compiled by V. Peshkov Tehred I. Veres Proofreader T. Kolb Order 2297/58 Circulation 816 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab, 4/5 Production and printing company, Uzhgorod, st. Project, 4 FIG. 2