It Is Alive!!! Bwahahahahahaha

[cheesy]

Originally Posted by FastDoc

Welcome home.

Dog and cat love is good love. In some (many) cases I prefer it to human love...

I've had both moose and lobster in Maine. I prefer the moose.

I feel old just working on my normal sized stuff. Cuts take longer to heal, my hands get sore, my back hurts. I know how you feel!

Good on you for keeping it up though!

Thanks, Doc. Dasher is my little buddy. Used to greet me at the door when I'd get home but at 15 years of age now, I usually have to wake him up when I come in. Still sleeps on my pillow with me.

The kids in ME are only 12 miles from the coast, so they get fresh lobster off the back of a pickup for less than hamburger. In fact, they do CSA, so they rarely go to a grocery store anymore.

Pretty much a wasted week. Bicycled into work on Monday but spent a good part of the day sneezing my brains out. Had a diabetes follow up on Tuesday and was still feeling crummy, so my doc checked me out. He congratulated me for developing a pollen allergy at 57 years old. Prescribed something that MIGHT make me drowsy. HAAAA. In bed the last three nights by 8pm. :wink:

Feeling pretty good today. Took youngest kid out to dinner for her b'day. She turned 30, so Mrs. C and I are officially old.

The MOSFET stuff showed up yesterday, so that's tomorrows' project.

[Weldangrind]

I was in my thirties when I developed pollen allergies. Bummer.

[cheesy]

Originally Posted by Weldangrind

I was in my thirties when I developed pollen allergies. Bummer.

Mrs. C has been all her life. Now I understand what the whining was about. On the other side of the coin, I actually sought out medical help. Something that Mrs. C hasn't done since we got married.

Enough of 'Living With Snot', progress was made today. No pics but started out by breadboarding the MOSFET temp control. Goofy thing actually might work. Only consists of three main parts, an N-channel power MOSFET, 10K trimming pot, and a 10K NTC thermistor, plus a circuit board and a heatsink for the MOSFET. The trimmer adjusts the cut-in temp for the fan, the themistor is the sensor, and the MOSFET is the heart of the system.

In my initial futzing, I used my 12v power supply and the 'zuki cooling fan with the breadboard wired between them. Switch on the power and adjust the trimmer until the fan shuts down(I had a mini digital VM wired in, too). Hold the thermistor between my fingers and within 10 seconds the voltage would climb, fan would start and ramp up to speed. Let go of the thermistor, and the voltage and speed would drop to zero. No switches, no relays, just a keyed power source with the thermistor in contact with the rad.

Will be building a usable unit tomorrow sans the heatsink, pics then. Have none on hand but have some big heatsinks on my bench at the shop from an old TV that are designed for the TO-220 case of the MOSFET. (That little bugger gets HOT)

In other news, the engine is in the frame. Started running wires and cables and found the clutch cable a bit 'gummy'. Lubed that up and decided I'd had enough fun for one day.

[cheesy]

Pics. :wink:

Parts. L to R, 10K NTC Thermistor, N-channel power MOSFET, bit o' circuit board, and a 10K trimmer pot.

The thermistor is already insulated because I used it in the futzing yesterday.

What I'm making.


Initial assembly.



Pretty much the final assembly.

As you can see, I scrounged a heatsink. Not shown, Weatherpak plug. If you were to ask me how it works, my first response would be 'Sorcery'. But, in a nutshell, as the temp rises, the resistance drops in the thermistor. When that resistance exceeds that of the pot, the fan kicks on. A caveat, I could be 180 degrees off and it's a rise in resistance. Which is why I said sorcery.

Still need to suss how I'm going mount the unit but I have some ideas requiring brass tubing and PVC pipe.

Got a new Bilt Apollo Modular Helmet today, too. http://tinyurl.com/cbxst3c
Got the Matte Black one.

[Corvairkid]

hey folk just poking my noise around looking for help with a zs250gs with no spark :( a dealer sold me a lifan 300cc box and told me it would work but sill no spark .... nice bikes and mods btw i never thought there would be such a big Chinese big community

[Weldangrind]

Corvairkid, I presume that Spud is out enjoying the good weather, and he'll likely be the best resource for you. In the meantime, please keep your Zong discussion in your Zong thread, and don't hijack others.

Cheers!

[Weldangrind]

Cheesy, you don't feel that there is enough load in the fan to warrant a relay?

[cheesy]

A relay is plan B, Weld.

I'm going to put an ammeter in series with the unit and using the Hondas' output, see what the amp draw is on startup and run, then go from there. If less than 3 on startup, I probably won't.


Didn't use an ammeter in the initial test as my cheap-ass power supply is maxed out at 11.9V 2A.

[cheesy]

A bit saner explanation on how the circuit works. The emphasis is mine. From Wikipedia:

NTC thermistors can be used as inrush-current limiting devices in power supply circuits. They present a higher resistance initially which prevents large currents from flowing at turn-on, and then heat up and become much lower resistance to allow higher current flow during normal operation.
These thermistors are usually much larger than measuring type thermistors, and are purposely designed for this application.

This why I'm thinking about not using a relay. The fan behaved this way in the test. Start off slow and build up to max speed.

We'll see later this week.

[Weldangrind]

Hi, my name is Derryk. I'm a relay addict.

I figure, why not just use the output of the thermistor to trigger a relay? The ISO-standard relays are cheap as chips, and they can handle any current level you wish. Perhaps the current draw of the fan is within the thermistor specs, but that's during testing in a vacuum. Additionally, in-rush current is really difficult to measure.

Not an expert. That's probably why I use relays so much.

[cheesy]

Originally Posted by Weldangrind

Hi, my name is Derryk. I'm a relay addict.

I figure, why not just use the output of the thermistor to trigger a relay? The ISO-standard relays are cheap as chips, and they can handle any current level you wish. Perhaps the current draw of the fan is within the thermistor specs, but that's during testing in a vacuum. Additionally, in-rush current is really difficult to measure.

Not an expert. That's probably why I use relays so much.

You do have a valid point.

I want to see how this set up behaves with 14.5v input in real life conditions. If adding a relay to the circuit is needed, I'll add one.

[cheesy]

A bit done last night. This is where the thermistor will go.

Took four attempts to get the tubing cut to the right size to fit the thermistor.:oops:

And I hadn't even been drinking.

[Weldangrind]

Originally Posted by cheesy

Took four attempts to get the tubing cut to the right size to fit the thermistor.:oops:

And I hadn't even been drinking.

Maybe that's the problem. Single malt fixes everything. That, or some mead.

What type of thread is in the drain plug? Can you match it with a brass piece? Perhaps you could create a tee there and screw a probe in, rather than using epoxy.

[cheesy]

Thought about that before going this route. M12x1.25 thread on that plug, not your typical "Ace is the place" fastener thread`

[cheesy]

I can see the finish line.

Got more done today than I have since October. Carbs on, stock wiring back in place, all the 'what the heck is this for' back where they it from. Just need to hang the rad, exhaust, rear brake, and fluids then I can punch the starter button.

BTW, WnG, just in case the thermistor doesn't work as well as it did on the bench. :wink: