Ryobi cordless/corded blower - how does it work? - Page 1
Forum section: electronics / general

author: NiHaoMike
author_rank: Super Contributor
timestamp: February 07, 2015, 08:28:18 pm
content: https://www.ryobitools.com/outdoor/products/details/590How do you think they designed it to work on either a 18V battery pack or 120V mains?

author: IanB
author_rank: Super Contributor
timestamp: February 07, 2015, 08:59:20 pm
content: Quote from: NiHaoMike on February 07, 2015, 08:28:18 pmIt wouldn't be hard to put a compact 18 V switching power supply in there, surely?

author: NiHaoMike
author_rank: Super Contributor
timestamp: February 08, 2015, 06:33:46 am
content: That was my first thought, but it looks a little small for a PSU of that power level. I wonder if there's a simpler explanation like some extra windings on the motor to make it dual voltage.

author: SeanB
author_rank: Super Contributor
timestamp: February 08, 2015, 08:02:56 am
content: Dual speed means they probably wound the motor for 115VAC operation and made the winding resistance low enough that it will run at close to full power from 18VDC. Use a proper wire diameter and a larger rotor for extra room and you can run a motor like that. No SMPS needed, just going from being a series wound DC motor to being an universal motor. Speed control could be easy as well, just a chopper that uses a Mosfet to do cycle dropping on Ac and PWM on DC, with a switch to bypass it for full power.

author: Orpheus
author_rank: Regular Contributor
timestamp: February 10, 2015, 06:37:25 pm
content: Thanks for bringing this up. I have a lot of cordless Ryobi tools, and have characterized their current draws fairly well, over years of hobbyist battery life/reconditioning experiments, I often use my Ryobi batteries to power electronics project, too. (since Ryobi prices their basic drill+battery set the same as a replacement battery alone, I buy the set so I can use the drill motor for robotics and the crude charger boot/wallwart for electronics projects. The cheap charger they sell in the loss-leader drill kit is crap; their other, more expensive kits come with VASTLY better chargers)Looking into it, I found a broad market of inexpensive 120VAC->18VDC Ryobi battery eliminators. It seems the third party inventors got there first, and Ryobi may have picked up on it after seeing the popularity. These will be a big help for my tools and electronics projects. THANKS!Amusingly, just as Ryobi picked up the idea from third party vendors, the knock-off specialists stole the idea from Ryobi (as they do with everything else). I mention this because it seems to have pit two 'generations' of third party manufacturers against each other, forcing the rip-off artists to be even cheesier/sloppier than usual to compete. The reviews say you need to be particularly careful which brand you buy. (Unless you use Ryobi tools enough year-round, as I do, to justify the Ryobi branded unit. Remember: batteries slowly deteriorate as they sit unused, too)Then again you might simply repurpose a dead Ryobi battery and a 19v 96W laptop supply.

author: SeanB
author_rank: Super Contributor
timestamp: February 10, 2015, 07:13:45 pm
content: Like I did with an old cordless drill, as the cost of repacking the battery ( again) was way too expensive. Just modified it to have a short cord, and am using a 12V 7Ah SLA battery ( easy to charge, I have a few chargers for them) as a power source. Works just as well, and the cord is long enough to allow it to sit in a jacket pocket in use, and without the extra kilo of mass on the drill using it up a ladder is easier. Only about 30 holes per charge, but I just keep a few spare batteries in the tool trolley.