Products
MODEL 261R-002 FREQUENCY TO VOLTAGE CONVERTER
Description
The Model 261R-002 frequency to voltage converter consists of up to seven converter modules and one power supply module (Model 819) in a 19" W x 7"H rack adapter. Each converter module has a front panel DC output voltmeter with a 0-10VDC scale for overranging.
The converter is used to detect the zero-crossing of any waveform and to provide a scaled analog output voltage proportional to the frequency of the wave form, probe, displacement probe or photonic sensor. In addition to the DC output voltage, pulse outputs are provided for operating an external frequency counter and range checking. Because it is typically used to measure rotational speed, six nominal scale ranges plus a full scale vernier are provided at 200, 500, 1000, 5000, 10000 and 20000Hz.
Other features include provision for both internal and external calibration, computer command and signal-level discrimination. Transformer input coupling provides up to one KV RMS CMV isolation between the input and output circuits. The analog output voltage is independent of the normal mode signal voltage which may range between .02 V peak to 100 V peak.
A master crystal oscillator in the power supply module provides a precise 10KHz output. This cal-signal goes to each frequency to voltage module where it is divided as needed to provide a one-half full scale internal cal-frequency. Provision is made for the modules to operate from externally supplied cal-frequencies.
Specifications
Input: 0.025V peak to 100V peak (O Hz input = OVDC out)
Input isolation: Transformer isolated to 1000V RMS
Common mode rejection: 2.5VRMS DC to 1kHz will not trigger the unit
Signal discriminator: Adjusts input signal threshold from .02V to 10V with lockable front panel potentiometer
Input frequency: Six switch selectable ranges and a multiturn vernier provide full scale output (+5VDC) for any input frequency between 100Hz and 30kHZ.
Frequency range: Nominally 200Hz, 500Hz, 1kHz, 5kHz, 10kHz and 20kHz
Pulse output: +5V rectangular pulse tracks input frequency
DC output: 0 - +5 VDC full scale
DC offfset: +5 VDC full scale output can be offset to zero.
Range check: 500Hz +5 VDC ±2% rear panel output
Output linearity: Better than ± .025% of full scale from best zero based straight line
Output accuracy: ±0.1% of full scale reading
Transient response: A two-position, PC board mounted switch selects either a transient response time of less than 20/f (seconds) in the high position and less than 60/f seconds) in the low position, where f is equal to one-half of the full scale frequency range
Ripple: With the transient switch in the high position, ripple on any range is less than 30MV peak/peak at 10% of the full scale frequency;
with the transient switch in the low position, ripple on any range is less than 10MV peak to peak at 10% of the full scale frequency
