Pedal powered generator

I have an ancient (1967!) Slo-Syn SS150-1077 driving motor that I bought about 25 years ago to use as a generator motor. It's rated at 120V and .4 A. It's rated at 72RPM so it's got gears in there somewhere. It should be easy to add some bike cranks and drive it via chain with very little gear ratio change. It requires a cap and a resistor to run it from 120VAC. I'd like to use it as a pedal powered generator and am hoping that the brain trust here will be able to help me do that or tell me that it's not a good idea.

Here's the schematic for AC operation:



I'd like to use it to charge a 24V battery. That can then be used by an old APC UPS to run 120V things.

- Can the same cap and resistor be used to align both phases of the motor when used as a generator?
- Can the resulting output be run through a full rectifier diode array and then through a DC-DC convertor to reduce the voltage to around 24 VDC?
- Do I need to use one of those solar charging things to make sure that it only charges the battery and doesn't discharge it or can I do that another way?

According to this page: https://www.ahs-antriebstechnik.de/images/PDFDateien/Service/C4001-SS-Obsolete.pdf
The resistor and capacitor values are 250 ohm, 25 watt and 3.75 ufd, 330V.
https://www.mouser.com/ProductDetail/Vishay-Dale/RH025250R0FE02?qs=sGAEpiMZZMukHu%252BjC5l7YWZuL2P47FOvVS39wZKNMBk%3D
https://www.mouser.com/ProductDetail/Cornell-Dubilier-CDE/23FD3304A-F?qs=rVFmcZtbgVjhD%252BUdpF%252BkjQ%3D%3D

Thanks!

Warren

That's a stepper motor. I was surprised to find that stepper motors are easy to convert to generators. Your motor consumes 48W at its rated power, so in principle if you pedal it at 72 rpm, it will make about 120V and 48W minus motor and conversion losses.

I once made a generator bike using a 24V brushed scooter motor as a generator. Rather than doing voltage conversion, I used a 12V battery to set the system voltage (and deliver uninterrupted power to the load). On the generator output, I placed first a relay that switched on at about 7-8V, and then a power diode to prevent the battery from driving the motor/generator. The pedals had little resistance until the generator RPM rose to exceed the battery voltage, at which point the voltage difference pushed current across to the battery.

You could do something like that, but the working voltage for your generator would be much higher than 24V. If you gear it down for lower raw output voltage, the output power would drop dramatically to single digit watts.

Something like a solar/wind charge controller rated to handle the range of voltage and power from your generator would likely be the easiest solution for you. Usually those things run lower input voltage, though.

https://www.eeweb.com/stepper-motor-generator/

[youtube]lAvCYuNxGS8[/youtube]

It wouldn't be my thinking that a piece of legacy equipment from 1967 would be viable in 2020. Not the device itself, but it's components. Permanent magnets will have lost power, capacitors may have leaked, bearings may be dried out. Is there a plan to ascertain the functionality of the device? There are current (swidt?) model pedal powered generators on Amazon, and they aren't that expensive. They are designed from go to be generators. The voltage(s) they produce are compatible with 21st Century applications. I am not sure what is driving this project. Is it just to charge a battery pack, or power an e-bike? 24V isn't a voltage I recognize as being good for anything anymore. It is too low for most applications I can think of.

https://youtu.be/S4O5voOCqAQ

john61ct said:

https://youtu.be/S4O5voOCqAQ

Click to expand...

We have lots of things to power that aren't resistive heaters. My generator bike powered a laptop computer and some CFL lights for an outdoor art installation.

Bearings seem fine. I'm assuming that these are old school ceramic permanent magnets. Unless they are abused by heat or physically damaged permanent magnets retain their magnetism for a very long time. I have verified that the winding still have resistance. I need to buy the capacitor and resistor so they'd be new. Looks like about $25 in parts.



Twisting the motor with my hand produces about 12VAC on each winding!

Alternatively I could use a Astro 3210 motor that is languishing but that would need to be geared much higher.

My goal here is to make a generator from (mostly) existing parts. What it will get used for depends on how well it works.

Chalo said:

john61ct said:

https://youtu.be/S4O5voOCqAQ

Click to expand...

We have lots of things to power that aren't resistive heaters. My generator bike powered a laptop computer and some CFL lights for an outdoor art installation.

Click to expand...

Sure! Obviously the takeaway is it works, if energy needs are low and the user is fit and motivated.

Many people underestimate the former and overestimate the latter

so I was just pointing out the concept's got practical limitations.