ELM303 View Datasheet(PDF) - Elm Electronics
Part Name
Description
Manufacturer
ELM303 Datasheet PDF : 5 Pages
| |||
ELM303
Example Applications
The circuits on this page show two different
configurations for the ELM303. In each case, one should
keep in mind that these are experimenter circuits that
require some extra care to protect against electrostatic
discharge, etc. The other concern is the possibility of
backfeeds from the two different power supplies
(camcorder and ELM303). To prevent damage to the
ELM303, always make sure that it is powered up before
connecting to the camcorder.
Figure 2 at the right shows the ELM303 in a typical
security configuration. The internal pullup resistor on pin
4 is used to advantage to keep I0 and I1 at high logic
levels while the alarm contact is open. With I2 at a low
level and D0 at a high, this configures the circuit for 10
second recordings every hour. Note that all three
resistors shown are for ESD protection, and aren’t
necessary for circuit operation.
When the alarm contact closes, the three ‘I’ inputs
are all at a low level, causing recording to start and
continue until the contact is released.
Figure 3 is a programmable system using ‘DIP’ type
switches to allow the settings to be changed as needed.
Power is from three AA size alkaline cells, which give
approximately 4.8V when fresh. Strictly speaking the
supply should be at 5V to be consistent with the Control
L (LANC) system, but in practice, this works quite well.
Three cell battery holders are available for this type of
application, but if one can’t be found, shorting out one
position in a four cell holder will accomplish the same
thing. Of course, a regulated 5V supply would be
preferrable if one were available.
Operation of either circuit is similar. The ELM303
circuitry is powered up before connecting it to the
+5V 0.1µF
1
2
3
4
22K
Alarm
Contact
8
7
6
5 +5V
120Ω
120Ω
4
5
2
3
1
Control L mini DIN
Cable Connector (male)
Figure 2. Alarm Triggering
camcorder, and the camcorder is powered and placed in the
camera / standby state. The cable between the two is then
connected and approximately one minute later, the camera
will record one sequence, and will power down. After the
duration set by the Interval pins, recording will be initiated
again.
Some cameras do not have power control inputs, so will
require additional circuitry in order to take advantage of the
power control capabilities. A toggle type circuit (driven from
the power output pin) could be constructed for this purpose
by the more adventurous experimenter, but is beyond the
scope of this document to describe.
Experimentation will determine the best settings to use
for each of your applications. For plant growing experiments,
try using the 60min / 1sec setting. You will find that 1 second
is a little long for creating your own animations, but may be
just right for others…
VDD
33K
33K
33K
VDD = 4.5V
+
0.1µF
1
8
2
7
3
6
120Ω
120Ω
4
5
2
3
1
Period
Set as per Table 1,
closed = L and open = H
4
5
VDD
33K
Control L mini DIN
Cable Connector (male)
Duration
closed = 1 sec
open = 10 sec
Figure 3. Time–Lapse Controller
ELM303DSA
Elm Electronics – Circuits for the Hobbyist
< http://www.elmelectronics.com/ >
5 of 5
Share Link: 