[Peter]’s dad recently rekindled his love for Lionel trains and wanted a bell to keep the crossings safe for O gauge drivers and pedestrians. Using parts he had lying around and a doorbell from the hardware store, [Peter] concocted this DIY train crossing bell at his dad’s request.
The idea was to make the bell chime about once per second. To achieve this, [Peter] used a non-repeating electro-mechanical doorbell that emits a single note on continuous press. You could also roll your own bell with a spring-loaded solenoid and something bell-like for it to strike.
[Peter]’s three-stage design uses a full-wave bridge rectifier to convert the AC from the train transformer to DC. He drops it to 5V and sends it through a 555 and some resistors to set the frequency and duty cycle. His output section translates the voltage back up to match the input desired by the doorbell. [Peter] included a 1N4002 as a back EMF snubber to keep feedback from damaging the power MOSFET. Stick around for his demonstration video after the jump.
A solid brass bell and cast frame with adjustable screw! I would like to go to that store. Probably pre-war.
Yea the HAD summery is off. That particular bell came from my scrap pile. Not exactly sure where I got it but it was used and I have held onto it for the last 15 years at least. (been through at least two moves based on the box I got it out of.)
Since that is a one of a kind I had in the article you can get a functional replacement at a hardware store in the form of a door bell / chime.
Sorry for the confusion.
They also make large bells for bicycles, some people like the lower ding sound. So you could use that as source too, you probably can get them on ebay and such for a buck or two.
Addendum: Obviously you’d need an actuator, but I’m sure HaD visitors can figure out something for that.