Sorry all I've been rather ill for the past week and have not had the mental capacity to work on this. Fortunately things are looking up now and I'll head to the post office tomorrow to enquire about shipping.
In the mean time I've jotted down some installation instructions. A bit of electrical splicing will be needed to get the small version working, however the larger version should be quite easy to install if you can figure out how to connect it to the battery terminals.
A typical circuit inside a red-dot finder will have a battery, a switching / brightness mechanism, and the laser maybe including some current limiting resistor along the way all hooked up in series.
Installation for the small version:
- Open the Red dot finder and identify the cables that go from the battery to the rest of the circuit.
- Cut the batteries from the rest of the circuit.
- Connect the Batt+/- terminals of the momentary pushbutton to the battery.
- Connect the Dot +/- terminals of the switch to the rest of the circuit. Effecively you've just spliced this thing in the way of the battery.
- Turn on the red-dot finder and then press the button and it should light for 60s.
Installation for the large version:
- Remove battery from red-dot finder.
- Connect the +ve and -ve terminals to the + and - leads of the battery holder *
- Turn on the red-dot finder and then press the button and it should light for 60s.
* The idea is to replace the battery with this circuit. To connect to a typical coin cell battery you need some way of pressing the leads to either terminal in the battery holder. A small 20mm circle of bulsa wood, or a small disc of plastic would do the job. I have had success making a sandwich of a 5c piece, the wire, a folded piece of paper, the other wire, and another 5c piece and slot that mess into where the battery goes (see picture). Though I'm sure some of you clever people could think of something more reliable, such as the same thing with a lot of hot glue
**
Erratum on attached picture instructions: The picture shows the potentiometer attached to the high side of the laser and cables setup such that green > potentiometer, and blue > laser. Based on feedback some finders may have the potentiometer installed on the wrong side of the laser. In this case swap the green and blue leads in the instruction so that green > laser and blue > potentiometer.
You can't damage your red dot finder if you plug in this unit backwards. Laser diodes act like LEDs and will only pass current one way so hooking it up backwards means you will simply see no signs of life.
