1
7
8
9
10
11
12
6
5
4
3
2
1
2.37 (60.2)
1.77
(45.0)
SOCKET P/N 2300200
(ORDER SEPARATELY)
.88
(22.4)
4.44
(112.8)
* RANGE ADJUSTMENT (VOLTAGE & CURRENT OUTPUT)
.84
(21.3)
2.69
(68.3)
2.31 (58.7)
.84
(21.3)
SOCKET
P/N 2300200
.16 (4.1) DIA.
2 HOLES
* ZERO ADJUSTMENT (CURRENT OUTPUT ONLY)
* 20 TURN SCREWDRIVER
ADJUSTMENTS ACCESSIBLE
THROUGH TOP
DELIVERS ANALOG OUTPUT PROPORTIONAL TO INPUT
PULSE-RATE (FREQUENCY)
ACCEPTS VARIABLE PULSE-RATE INPUTS FROM A WIDE
VARIETY OF SENSORS
DUAL SIGNAL OUTPUT, 0 TO 10 VDC PLUS SELECTABLE
SIGNAL CURRENT OUTPUT OF 0 TO 1 MA OR 4 TO 20 MA
SELECTABLE FREQUENCY RANGE RATINGS FROM 30 HZ TO
10 KHZ
ACCURACY (LINEARITY) 0.25%
SWITCH SELECTABLE FOR 115 OR 230 VAC
DESCRIPTION
The Model PRA2 is a convenient plug-in module that provides voltage and
current analog output signals proportional to the pulse-rate
(frequency)
of the
input signal. In typical applications the PRA2 input is supplied by a machine
mounted sensor that generates a signal which has a frequency proportional to
machine or process speed. The PRA2 converts the frequency content of this
signal to analog form for operating chart recorders, supplying speed control
signals, or driving other controls and indicators that require analog input.
The PRA2 develops an internal
“constant-area”
pulse from the
negative
going
edge of each input pulse or wave form cycle. These
“Constant-area”
pulses are fixed in voltage amplitude and time duration. The PRA2 then takes
the average of a train of these pulses to generate an output voltage level
proportional to the frequency. Another circuit within the PRA2 monitors the
voltage output and produces a current output signal that will deliver either 0 to
1 or 4 to 20 mA, as determined by a set-up switch.
This unit is available with five overlapping adjustable range ratings, each
rating providing a calibration adjustment to deliver maximum output over an
input frequency range of approximately 3.3:1. Since the PRA2 develops an
output by averaging pulses, an inherent response time is involved
(See response
table, next page).
The minimum response time is fixed for each range rating. It
is longest for the lowest range rating and decreases as the frequency range rating
increases. Response time must be considered, when using the PRA2 to provide
closed-loop speed feedback signals, to avoid stability problems. For speed
feedback applications it is usually advisable to select a high frequency range
coupled with an appropriate sensor arrangement that delivers a high pulse rate.
The internal output filtering supplied for averaging purposes is kept to a
minimum to provide the fastest practical response time for each range rating.
Extra external capacitance can be added to provide more filtering if required.
The plug-in module mates with a heavy duty, CSA approved base mounting
socket with pressure clamp screw terminals that accept stripped wires without lugs.
SPECIFICATIONS
1.
PRIMARY SUPPLY VOLTAGE:
Switch selectable for 115 or 230 VAC
±10%, 60 Hz; 8 VA
2.
SENSOR OUTPUT POWER:
+12 VDC ±5% regulated, 60 mA max.
3.
SIGNAL INPUT CHARACTERISTICS:
See
“Input & Output Switch
Set-up”
section.
4.
MAX. FREQUENCY ADJUSTMENT:
30 Hz to 10 KHz
5.
SIGNAL VOLTAGE OUTPUT:
0 to 10 VDC @ 10 mA max.
6.
SIGNAL CURRENT OUTPUT (Selectable):
0 to 1 mA into load resistance range 0 to 4 K
.
4 to 20 mA into load resistance range 0 to 250
7.
LINEARITY:
±0.25% of full range setting.
8.
VOLTAGE/CURRENT OUTPUT TRACKING:
Current Signals follow
voltage signals within ±3% of full range setting.
9.
RESPONSE TIME:
See table on next page.
10.
OPERATING TEMPERATURE RANGE:
0 to 60
o
C.
11.
WEIGHT:
PRA2 - 8 oz
(226.8 g);
Mating 12-Pin Socket - 2 oz
(56.7 g).
ORDERING INFORMATION
MODEL NO.
DESCRIPTION
PART NUMBERS
PRA2
Pulse Rate to Analog Converter
PRA20000
Socket, 12-Pin
2300200
MODEL PRA2 - PULSE RATE TO ANALOG CONVERTER
DIMENSIONS In inches (mm)
Bulletin No. PRA2-C
Drawing No. LP0540
Released 10/12
Tel +1 (717) 767-6511
Fax +1 (717) 764-0839
www.redlion.net
