Week 10 – More.

This week was simply more – more prototypes of the TapCap, more failed circuitry, and more attempts at getting them both just right.

As for the circuitry, I initially tried copying this setup:

 (Image via CircuitDigest) 

Here, the white dome-shaped object is the motion sensor, and the LED is the blue bulb on the right side. 

I intended to replace the LED with the push-pull solenoid, and if that worked, I would solder it together to insert into the TapCap. Unfortunately, however, when I wired up the solenoid, the solenoid refused to activate. Upon further investigation, I found that the answer lay not in a faulty setup, but in the design of the motion sensor itself. It could only output 3.3 volts, while the solenoid required a minimum of 4.5 volts. 

After replacing the solenoid with one that activates at as low as 3 volts, I believed my problems to be solved. Unfortunately, however, that wasn’t the case. Even while using the new low-voltage solenoid, the circuit refused to work.  

 After more research and looking through various other circuit designs, I deduced that I would most likely have to use a separate power source for the solenoid, as the motion sensor probably could not power it alone. After watching a YouTube video, I created the following circuit:

However, this circuit failed as well! The circuit worked when I reversed the polarity, but bypassed the motion sensing. I’m working on figuring out why this happens with my mentors currently.

As we move into the final week, I’ll be prepping my presentation and finishing up my prototype!