On Wed, 5 Aug 2020 17:29:20 -0700 (PDT), wrote:

On Wednesday, 5 August 2020 23:14:06 UTC+1, Chris Bacon wrote:
On 05/08/2020 22:19, T i m wrote:
On Wed, 5 Aug 2020 18:24:58 +0100, Chris Bacon
wrote:

At least the scooter you're looking at has sufficient ground clearence
not to get stuck on a pebble (!), or if a wheel goes off the path and
onto the grass, which the Pride Go-Go "Elite Traveller 4" thing my mum
had could do. Mind you, the "disconnect drive" feature had a handy
safety feature that if it was disconnected, the drive would brake if
freewheel speed got above "brisk walk", and it was handy to be easily
dismantlable by means of 1 lever to stick into a car.

I always wondered what would happen with those machines if an output transistor failed. Wouldn't it suddenly apply full power uncontrollably?

I wondered the same and there is no emergency cuttoff button (on the
ones I've played with anyway).

I guess the idea is that with a top speed of 8mph you aren't going to
go *too* fast but even that to a dead stop wouldn't be good for many
(older especially) people?

It's possible the 'ignition switch' drives another transistor or power
relay?

One thing that did surprise me when the Mrs first rode the scooter
round to Mums as it seems that the single (rear) brake isn't
interlocked with the throttle and you *can* have the throttle on and
the rear brake. ;-( rolls eyes

Now, there could be a reason it isn't ... like what if the brake did
cut out the throttle, you came to a halt with the throttle sill on
full and then you released the brake? You would have to design it so
that it had to see the throttle back to zero before it enabled power
again?

Some motorbikes / cars won't start unless you have you foot / hand
operating one of the controls and on some motorbikes they will cut the
ignition as soon as you try to take the gear out of neutral and still
have the side stand down.

Cheers, T i m