E10 bulb with lens are great for pointed focus. Those bulbs are common in vintage pencil beam flashlights like Sea-Gull Pocket Flashlight FS 008 model. If you never saw the model can perform a web search. In 2017 that model’s old stock of unopened sells at $20 to $40 per piece. Those E10 bulb with lens has LED version but neither cheap for easily available. We can add circuit, use glass lens. Here is DIY led replacement bulb for E10 bulb with lens. Of course the same principle can be added in other type of bulbs.
DIY LED Replacement Bulb For E10 Bulb With Lens
Find a such bulbs whose filament blown away. You have to perform microsurgery with the bulb. You can not simply break the total glass bulb to destroy the lens. It will need to take out the glass bulb from one such by dipping in concentrated hydrochloric acid or nitric acid. Metal will get dissolved in the process and the bulb with other fillers will remain. You need to use tools used for spectacle glass drilling cutting to cut the bulb at base. Initially you need to make a drill – it is risky work.
In another such bulb, you’ll break the glass bulb and clean the inside. We need the intact metal of this second piece.
There are various options of LED – like SMD LED which we talked around in SMD components. There are SMD LED of 5v, 3.3v manufactured by companies like Samsung. you have to test on breadboard to check it working.
DIY LED Replacement Bulb Circuit
We are talking about SMD LED of 5v, 3.3v but battery is two AA supplying hardly near 3v at full charged condition. You need a small circuit to supply constant 3.3v from low voltage. Which is nicely shown in this blog post :
This was his thing with a normal LED :
Here is the circuit originally designed by him :
You can understand that it is difficult project than it seemed. You have to put the circuit with SMD LED inside the bulb’s metal part, put the glass bulb with lens on it and fix with silicon or epoxy adhesive which are used for aquarium glass joining.