Simpson MINI-MAX M235 User Manual

Shallow Depth Indicator - Less Than 2.5" (60mm) of
Space Required Behind the Panel

Stackable Mounting Bracket Included for Easy
Installation

3-1/2 Digit, 0.5" (12.7mm) High LCD with Optional
Negative Image, Bright Red Backlighting

Standard Screw Terminals for Easy Installation

Two Frequency Ranges: 20 - 199.9Hz or 20 - 1999Hz

Choice of RMS or Square Wave

85-250VAC Power

2.84"

0.95"

0.13" Max

Panel Thickness

2.36"

.874"

0.16"

2.68”

Mounting Requirements

Insert the Mini-Max through the panel, and then slide the mounting brack­et on to the Mini-Max. The mounting bracket allows Mini-Max units to be
stacked side-to-side or top-to-bottom and maintain the DIN standard
panel arrangements in 24mm by 72mm multiples. Panel cutout instruc­tions for stacking multiple units are provided under “stacking features.”

Mini-Max M235 Series Digital Panel Meter

Installation and Panel Cutout

Simpson’s Mini-Max Frequency meters provide accurate,
stable, frequency indication in a compact, 60mm deep case.
Units have a 3-1/2 digit, 0.5" (12.7mm) LCD display and are
available with a bright red, negative image backlight option.
Display hold is a standard feature. Screw terminal connec­tors provide easy wiring of power supply and input signal.

A unique mounting bracket is provided to allow for vertical or
horizontal stacking of multiple indicators. All units feature a
3/64 DIN, high-impact plastic case. The standard units have
a clear viewing window, and the units with optional negative
image, red backlighting have a red window.

Frequency

.88"

2.68"

DISPLAY
Type: 7-segment LCD
Height: 0.5” (12.7mm)
Overrange indication: Most significant

digit = “1”; other digits blank

Backlighting:

Optional negative image, red LED backlighting

Polarity: Auto with “-” indication, “+” implied

POWER REQUIREMENT

85-250VAC @40-440Hz

Power Consumption:

2.5VA min/4VA max

ACCURACY @ 25ºC:
200 Hz: ±0.2% of input ± 0.2Hz

ACCURACY @ 25ºC: (cont.)
2 kHz: ±0.2% of input ± 2Hz

INPUT LEVEL: 500mV to 250VRMS at 1.0M

⍀

impedance OR 5V to 24V Square Wave (DC off­set 2V maximum)
Resolution: 200Hz = 0.1Hz

2kHz = 1Hz

CONVERSION
Technique: Frequency-to-voltage
Rate: 3 samples/second-typical

ENVIRONMENTAL
Operating Temperature: 0 to 55°C
Storage Temperature: -10 to 60°C

ENVIRONMENTAL (cont.)
Relative Humidity:

0 to 85% non condensing @ 40°C

Temperature Coefficient:

(

⫾ 0.02% of input ⫾ 0.2 digits)/⬚C

Warmup time: Less than 15 minutes

MECHANICAL
Bezel: .95" x 2.84"

(24mm x 72mm)

Depth: 2.36" (60mm)
Panel Cutout: .88" x 2.68"

(22.2mm x 68mm)

Weight: 3.5oz (99.2g)
Case Material:

94-0,UL-rated, glass-filled thermoplastic

Specifications

Wiring Display

Stacking Features

Input Signal: Connect the IN HI and IN LO to the signal to be monitored.

Supply Power: Connect the power to the L1 and L2 terminals. Backlighting power for the optional negative image, bright red LED backlight-

ing is supplied by the Mini-Max, so no additional external power supply is required.

Reading Hold: Connect HOLD to COM/HOLD. If this feature is not required, the HOLD pin may remain unconnected (open).

(Input Signal) IN HI
(Input Signal) IN LO

DP3
DP2
DP1

HOLD

L1 (POS) (Power)
L2 (NEG) (Power)
EX (NEG)
EX (POS)

DP COMMON
(HOLD)

These instruments are designed for maximum safety to the operator when mounted in a panel according to instruc-

tions. They are not to be used unmounted or for exploratory measurements in unknown circuits.

The mounting brackets, included with every Mini-Max, can
be connected together. Multiple units can be mounted in a
single opening, allowing perfect alignment.

To punch one hole for multiple units, be sure to adjust the
standard panel cutout dimensions as shown here; other­wise the meters will not fit properly in the hole.

Mounting multiple units is quick and easy. Install the first
meter (bottom unit first if stacking vertically). Position the
next mounting bracket snugly against the first one, and
slide the second meter into place. Repeat for remaining
units.

Vertical

2.68"

.071"

.88"

Standard cutout

Add to standard
when stacking

.88"

2.68"

Standard cutout

.16"

Add to standard when stacking

Vertical

Horizontal

Horizontal

Safety SymbolOrdering Information

Non Backlight
Negative Image Red

Mini-Max Frequency Indicators are configured by making an entry for each box.

Basic Unit Display DPM Power Supply Range Excitation Output

M235

0

0
1

0

81
82
83
84

3-1/2 Digit
Indicator

85-250 VAC

20-199.9 Hz RMS
20-1999 Hz RMS
20-199.9 Hz Sq. Wave (5-24V)
20-1999 Hz Sq. Wave (5-24V)

None

The WARNING sign denotes
a hazard. It calls attention to
a procedure, practice, or the
like, which, if not correctly
performed or adhered to,
could result in personal
injury.

SIMPSON ELECTRIC COMPANY 520 Simpson Avenue, Lac du Flambeau, WI 54538-0099 • [phone] • FAX [phone]

www.simpsonelectric.com Printed in U.S.A. Part No. 6-116256, Edition 9 06/08