GESPAC Water
Alarm Board
Specifications:
·
12 VDC
Power @ 100mA
·
Accepts
any 2 wire water sensor with probe to probe spacing of ¼”.
·
Board Size
Description:
The DTEC Ltd. GESPAC water alarm board provides 8
water alarm inputs along with provision for a synchronous to sin converter
module for use with a gyro compass and inverter. The water alarm board provides
indication and protection for 8 water alarm inputs. It also provides indication
of input power +12 VDC and the DC-DC converters isolated +12 VDC output. The 8
water alarm channels use an isolated supply with a relay output providing the
input signal to the GESPAC digital input card. The switched relay output
voltage can be selected to output either +5 VDC or +12 VDC as the system
requires. The board requires +12 VDC, -12 VDC (only for synchronous/sin
converter), and ground.
Stock Item. US$300.00
Circuit Description:
The circuit description for the 8 water alarms is the
same for each channel. When the 2 inputs are shorted together this causes the
NPN transistor to turn on. After this transistor turns on the led should
illuminate and the relay should be energized for that appropriate channel. When
the relay closes the output channel goes low and is outputted. This is active
low output and when the channel is not active it can be tied high to either +5
or +12 VDC by jumper JP1. A 7805 (+5 VDC regulator) is provided to supply the
+5 VDC level if this is the non active level of the digital input card. The
isolated supply (+12 VDC) is provided by the Lambda DC-DC converter . This is
to isolate the positive and ground rail on the input side of the circuitry. An
LED will illuminate for each water alarm being activated, the +12 VDC input
power and the isolated +12 VDC power.
The optional circuitry provided for the synchronous to
sin/cosine conversion for use with a gyro is as follows. The 3 gyro compass
outputs S1, S2 and S3 are inputs to the board along with the reference voltage
which is typically 24 VAC @ 400 Hz from the gyro inverter. Outputs from the synchronous
to sin/cosine converter are the corrected sin and cosine values. No circuitry
is provided on the board for adjusting the bias or gain of the values. The
converter circuitry requires +12 VDC, -12 VDC and ground to function.
For download of Schematic and General Arrangement in
DXF format go to Downloads.
Connector Pinouts
|
Connector
P1 Screw Type Term Block |
Description |
|
1 |
S1 Gyro
Compass Input |
|
2 |
S2 Gyro
Compass Input |
|
3 |
S3 Gyro
Compass Input |
|
4 |
Reference
Voltage for the Converter |
|
5 |
Water Alarm
Output channel #1 |
|
6 |
Water Alarm
Output channel #2 |
|
7 |
Water Alarm
Output channel #3 |
|
8 |
Water Alarm
Output channel #4 |
|
9 |
Water Alarm
Output channel #5 |
|
10 |
Water Alarm Output
channel #6 |
|
11 |
Water Alarm
Output channel #7 |
|
12 |
Water Alarm
Output channel #8 |
|
13 |
Water Alarm
Channel #8 Input A |
|
14 |
Water Alarm
Channel #8 Input B |
|
15 |
Water Alarm
Channel #7 Input A |
|
16 |
Water Alarm
Channel #7 Input B |
|
17 |
Water Alarm
Channel #6 Input A |
|
18 |
Water Alarm
Channel #6 Input B |
|
19 |
Water Alarm
Channel #5 Input B |
|
20 |
Water Alarm
Channel #5 Input A |
|
21 |
Water Alarm
Channel #4 Input B |
|
22 |
Water Alarm
Channel #4 Input A |
|
23 |
Water Alarm Channel
#3 Input B |
|
24 |
Water Alarm
Channel #3 Input A |
|
25 |
Water Alarm
Channel #2 Input B |
|
26 |
Water Alarm
Channel #2 Input A |
|
27 |
Water Alarm
Channel #1 Input B |
|
28 |
Water Alarm
Channel #1 Input A |
|
29 |
Isolated
Ground |
|
30 |
-12 VDC Input
Power |
|
31 |
Sin Output |
|
32 |
Cosine Output |
|
33 |
Ground -
Power Supply Common |
|
34 |
+12 VDC Input
Power |