paparazzi-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Paparazzi-devel] Opto-coupler to trigger a camera on Umarim


From: Christophe De Wagter
Subject: Re: [Paparazzi-devel] Opto-coupler to trigger a camera on Umarim
Date: Mon, 7 Jan 2013 09:06:05 +0100

When using an optocoupler you must pay attention to:

-the autopilot pins can only sink about 15mA (not 60 mA like many opto-leds need)
-the opto transfer ratio must be large enough for your load (=sensitive phototransistor)
-your particular camera must have a sufficient voltage across its shoot pin: e.g. 5v shorted to ground.
-To avoid polarity issues there are also special opto-switches (=optocoupler with 2 photo transistors in opposite directions)

On Jan 7, 2013 3:42 AM, "Eduardo Lavratti" <address@hidden> wrote:
No man ... the camera side are opto coupled ... so the current not go across the opto coupler! only the light go.


On Sun, Jan 6, 2013 at 8:16 PM, Michel GORRAZ <address@hidden> wrote:
Ok, the trigger current is probably really small, but the optocoupler's led current (umarim side) must be at least greater than the trigger current (camera side) multiplied by the "current transfert ratio" to be sure the optocoupler's transistor will be correctly saturated.

@+
Michel


2013/1/6 Eduardo Lavratti <address@hidden>
... current drawing of camera trigger ?
the resistor need to be between umarin and optocoupler ! the other side of opto-coupler are connected direct to camera shot button.


On Sun, Jan 6, 2013 at 4:40 PM, Michel GORRAZ <address@hidden> wrote:
Hi Joseph,

I should work, as long as you correctly calculate the LED resistor (related to the current drawing of you camera's trigger input...)

@+
Michel

2013/1/6 Joseph Muhlhausen <address@hidden>
Hi All,

This is my first post on the list. 

I recently got a Umarim from PPZUAV. 
I want to trigger a camera from one of the ADC using a 4N25V opto-coupler (http://www.datasheetcatalog.org/datasheet/vishay/83530.pdf

Based on the opto-coupler specifications I calculated that I need a 42 Ohm resistor from the IO to the Anode. and connect the Cathode to the Umarim GND.

The result should be 3.3V pulse from IO = Opto-coupler Transistor Closed

Am I reading that right?

Regards,
Joseph


_______________________________________________
Paparazzi-devel mailing list
address@hidden
https://lists.nongnu.org/mailman/listinfo/paparazzi-devel



_______________________________________________
Paparazzi-devel mailing list
address@hidden
https://lists.nongnu.org/mailman/listinfo/paparazzi-devel



_______________________________________________
Paparazzi-devel mailing list
address@hidden
https://lists.nongnu.org/mailman/listinfo/paparazzi-devel



_______________________________________________
Paparazzi-devel mailing list
address@hidden
https://lists.nongnu.org/mailman/listinfo/paparazzi-devel



_______________________________________________
Paparazzi-devel mailing list
address@hidden
https://lists.nongnu.org/mailman/listinfo/paparazzi-devel


reply via email to

[Prev in Thread] Current Thread [Next in Thread]