USB regulator...

Electrically assisted bikes, trikes, etc.
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[XAP]Bob
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USB regulator...

Postby [XAP]Bob » 23 Nov 2017, 9:27am

36 V battery has a USB plug on the side, but I want one from the 'brains' so that it can just be left in place, plugged in - switched on when the controller is on etc...

I haven't dug into my wiring yet, but I am guessing that there is at least an easy tap for a 36V post 'power on' which I could use if I could find a decent (efficient) 5V regulator. Only powering cameras, so not a large power draw, but it would mean that the cameras were 'just on' when I was riding...

Anyone done the required electronics previously?

Thinking something like:
http://www.hobbytronics.co.uk/d24v5f5-5 ... -regulator
Would be a good starting point.
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kwackers
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Location: Warrington

Re: USB regulator...

Postby kwackers » 23 Nov 2017, 9:39am

[XAP]Bob wrote:36 V battery has a USB plug on the side, but I want one from the 'brains' so that it can just be left in place, plugged in - switched on when the controller is on etc...

I haven't dug into my wiring yet, but I am guessing that there is at least an easy tap for a 36V post 'power on' which I could use if I could find a decent (efficient) 5V regulator. Only powering cameras, so not a large power draw, but it would mean that the cameras were 'just on' when I was riding...

Anyone done the required electronics previously?

A few minutes with a multimeter should tell you want you need to know. I'm not sure they'd be switching 36v, I think it more likely it's already regulated down to 5 or perhaps 12.

If it's 5 then its a bit tricky I think there's some 'resistor' logic in there so you can't just directly wire 5v to the socket (bit of googling required), otherwise a buck converter will do what you want. Plenty that already have sockets on but you can get them without.
eBay buck converter with sockets

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[XAP]Bob
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Re: USB regulator...

Postby [XAP]Bob » 23 Nov 2017, 9:44am

I'd have thought that there has to be a 36 switching done somewhere, else the motor would be 12V, not 36V...

My hope is that the 36V is available easily somewhere when the controller is powered up... That might be a different story, but as you say - time to grab the multimeter and figure it out...
A shortcut has to be a challenge, otherwise it would just be the way.
No situation is so dire that panic cannot make it worse.
A good pun is it's own reword

There are two kinds of people in this world: those can extrapolate from incomplete data.

kwackers
Posts: 11484
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Location: Warrington

Re: USB regulator...

Postby kwackers » 23 Nov 2017, 9:49am

[XAP]Bob wrote:I'd have thought that there has to be a 36 switching done somewhere, else the motor would be 12V, not 36V...

My hope is that the 36V is available easily somewhere when the controller is powered up... That might be a different story, but as you say - time to grab the multimeter and figure it out...

I'm thinking of the electronics. All the sensors on mine have a supply voltage (and leds etc). I'm thinking it unlikely since these feed back to the controller that they'd be 36v especially as this wouldn't be regulated. More likely the controller is running off a lower voltage.

(On the Bafang the motor has a lot of electronics in it and provides the supply for everything else. Since it has a lot of aluminium and thus heatsinking it would make sense if it provides regulated supplies for other stuff).

Ruadh495
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Re: USB regulator...

Postby Ruadh495 » 23 Nov 2017, 10:40am

Is there a lighting output from the controller? It will be 36V (mine is anyway) but easy enough to step down with a DC-DC converter. The controller must have regulated outputs for other things (the LCD for a start) but it might be quite difficult to tap them. They also might be quite easy to overload. I think I managed this with my lighting, but it failed closed circuit and nothing else seems to be affected. Just means the lights are switched by the battery key switch rather than requiring a long press on a controller button as well.

Just occurred to me that we might mean different things by "controller". I have both a controller and an LCD control panel, it sounds like your controller might be integrated with the motor, so you only have the control panel?

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[XAP]Bob
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Re: USB regulator...

Postby [XAP]Bob » 23 Nov 2017, 11:57am

OK - I have a 'black box' which goes in a seat pack on a normal bike, and a handlebar unit which displays power and selects the assistance rating.

I'd like to pull the power from the black box.

I've not seen a lighting controller output, but I can look...
A shortcut has to be a challenge, otherwise it would just be the way.
No situation is so dire that panic cannot make it worse.
A good pun is it's own reword

There are two kinds of people in this world: those can extrapolate from incomplete data.

Ruadh495
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Re: USB regulator...

Postby Ruadh495 » 23 Nov 2017, 12:45pm

The "black box" is what I'm calling a "controller" (mine's a silver box). Are there any unused connectors on it? Probably ordinary bullets.

How do you switch on the LCD backlight? Is it "hold down the "up" button for two seconds"? On mine that switched the "spare" 36V output as well. Or is it an LED handlebar unit? In which case you might have the output but not be able to switch it on...

Is there a key switch at the battery? If there is why not take a "tap" off the main leads from the battery to the controller?
Last edited by Ruadh495 on 23 Nov 2017, 12:56pm, edited 1 time in total.

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[XAP]Bob
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Re: USB regulator...

Postby [XAP]Bob » 23 Nov 2017, 12:46pm

Not as sophisticated as a backlit lcd... but yes, it’s a press and hold to start up the brain
A shortcut has to be a challenge, otherwise it would just be the way.
No situation is so dire that panic cannot make it worse.
A good pun is it's own reword

There are two kinds of people in this world: those can extrapolate from incomplete data.

Ruadh495
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Re: USB regulator...

Postby Ruadh495 » 23 Nov 2017, 12:58pm

Overlapped with my edit... I just though it could be an LED unit not an LCD. If there is a spare output connector on the controller it still might be worth trying holding down the increase assist button to see if that switches the spare output on.

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[XAP]Bob
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Re: USB regulator...

Postby [XAP]Bob » 23 Nov 2017, 1:01pm

I'll grab a multimeter some point this weekend hopefully...

If there is a spare tail then that makes it much easier than I was anticipating.
A shortcut has to be a challenge, otherwise it would just be the way.
No situation is so dire that panic cannot make it worse.
A good pun is it's own reword

There are two kinds of people in this world: those can extrapolate from incomplete data.

Ruadh495
Posts: 413
Joined: 25 Jun 2016, 11:10am

Re: USB regulator...

Postby Ruadh495 » 23 Nov 2017, 1:08pm

Just remembered you don't have a pedal sensor, IIRC? Do you still have three control buttons? Middle one switches on, the other two are usually for PAS up and down. A long press of "up" turns on the lights (which is the output we are looking for), long press of down engages "walk assist" (6kph until you release the button, which is generally pretty quickly as 6kph is a bit too fast, then you have to hold the button for 2 seconds to get power on again. Use the throttle instead.)

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[XAP]Bob
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Re: USB regulator...

Postby [XAP]Bob » 23 Nov 2017, 5:58pm

Hmm, don’t have an obvious 36v switched from the panel - looks like I have 39v straight from the battery on a connector though - and the battery has a main power switch...

[I’ve therefore ordered the regulator, it’ll be here when it’s here, then I can test it]
A shortcut has to be a challenge, otherwise it would just be the way.
No situation is so dire that panic cannot make it worse.
A good pun is it's own reword

There are two kinds of people in this world: those can extrapolate from incomplete data.