Corin Anderson (magellanic) wrote,
Corin Anderson

Making a Zappy go

So, we have these scooters at work, Zappys. The product management folks bought them a few years ago and had fun riding them around, but now Segways are all the rage, so the Zappys have fallen into disrepair.

Anyhoo, I've decided to adopt the Zappy fleet and bring them back to life. I mean, there's only a few Segways at work, but at least 8 or so scooters, just along the hallway near my desk. I borrowed someone's charger and warmed up the first battery. 20 hours later, I switched it on, pulled the throttle, and...


Er, hm. Something must be wrong. So, I go about taking the scooter apart, trying to figure out what's wrong. Is a relay blown? A fuse burned out? Something else? I take the entire thing apart, and spent a few hours this evening trying to figure out the circuit that controls the thing. As it turns out, it's a pretty clever circuit. But, to make a long story short, there's one more thing you need to know in order to ride the Zappy: you pull the throttle, you need to make sure the on switch is on (yes, I did that way early on), and...

you need to give it a rolling start.

Ugh! The Zappy is designed to not start the motor from a standstill. That sort of makes sense: cold-starting a DC motor is a big power load, so why not make the human rider just start with a kick? But, of course, I didn't figure this subtlety out until after I'de spent hours testing each component (okay, there were only 7 components, but I tested each!) and tracing the circuit. *heavy sigh* Well, at least I know that the scooter works. 8)

Oh, and, if you're interested: here's the schematic for the Zappy motor controller that I drew up. You can see (clearly, now that there's a schematic, heh) that the SCR controls if the relay can switch on the motor, but, paradoxically, the SCR is enabled only when the motor is generating energy (ie, turning).
  • Post a new comment


    default userpic
    When you submit the form an invisible reCAPTCHA check will be performed.
    You must follow the Privacy Policy and Google Terms of use.