I'm not saying I've never done that, but you seem to have a run going today.

What was the other one?

 

What was the other one?

Battery charger. I think it's Dr. Killjoy. You advised about a lithium battery long after OP said it was lead-acid.

 

Battery charger. I think it's Dr. Killjoy. You advised about a lithium battery long after OP said it was lead-acid.

Couldn't find any mention of that in the OP and I skipped a few of the replies.

And there's never a bad time to remind anyone who'll listen that lithium batteries need treating with respect.

And once again I started with; "if".

Neither case was "bad" advice - just not quite exactly tailored to the original question.

 

I like GopherT's idea of changing the bulbs to 25W. While it reduces the maximum luminosity available, since you were dimming the 40W bulbs anyway, it may be adequate.

If you choose this option, the GE 34420 bulbs might be a good choice. They're compact, have smaller (cheaper and safer) bases and an artistic envelope shape.

http://catalog.gelighting.com/lamp/incandescent/f=pygmy-clear/p=34420/d=0/

 

All you need is a power tool dimmer OR very simple to replace a 3 terminal semiconductor to 20a triac, and you can set what ever level you want.
Max.

 

I like the idea of changing the bulbs to 25W. While it reduces the maximum luminosity available, since you were dimming the 40W bulbs anyway, it may be adequate.

All the local stores have dropped the larger incandescent bulbs, and some are offering halogen capsules assembled in regular BC bases with a glass globe surrounding the capsule - so they look superficially just like regular bulbs.

The ones that claim the same brightness as regular 100W bulbs are actually rated about 70W or so.

This could be a solution to shaving some off the power rating without losing brightness, but I don't know what range of sizes are available or how a dimmer will react to a bank of parallel halogens.

 

@ian field
http://forum.allaboutcircuits.com/threads/lm317-issue.112936/
Your post #18
My post #19

"Not quite exactly tailored to the original question"?
If you don't think side-tracking the Thread with irrelevant information is, "bad", then I disagree with you.
IMO, Misdirecting the TS is almost like hijacking the Thread into a different topic.
At the very least, it's distracting to people that are trying to follow the logic of the thread by actually reading it. At worse, it could get the thread to wander off into a pointless and unproductive journey.

 

@ian field
http://forum.allaboutcircuits.com/threads/lm317-issue.112936/
Your post #18
My post #19

"Not quite exactly tailored to the original question"?
If you don't think side-tracking the Thread with irrelevant information is, "bad", then I disagree with you.
IMO, Misdirecting the TS is almost like hijacking the Thread into a different topic.

If you keep getting steamed up about things as trivial as that - you'll end up driving yourself potty!

 

@ian field
You think I'm having an emotional moment?
I thought I was having a very calm conversation.
In the future, I will simply refer these irrelevant posts to the Moderators.
That will remove my alleged emotions from the equation.

 

@ian field
You think I'm having an emotional moment?
I thought I was having a very calm conversation.
In the future, I will simply refer these irrelevant posts to the Moderators.
That will remove my alleged emotions from the equation.

You label misinformed advice as; "hijacking a thread" - and that's not getting emotional?!!!

 

Back to the diode, a 600 volt 5 amp diode would do it. Do you really even need the dimmer? The bulbs will be 60 to 70 % full brightness with just a diode and last about 100 times longer than they would running at full power. I doubt you would notice any flicker, an incandescent bulb's filament doesn't cool down that quick.

The diode is an old trick to make incandescent bulbs last longer, a 100 watt bulb and diode is a good replacement for a 60 watt bulb and will last for years instead of hours.

 

Did anyone mention making strings of two 40W bulbs in series. Then only 20W for each two bulb string.

Ken

 

The OP had access to a very interesting 40W incandescent bulb that is elongated with multiple filaments and elongated glass. He wanted to use that specific bulb because it is not available in other wattages and he liked the style. He didn't want flicker and he could not easily find a dimmer of sufficent wattage in London (UK) where he specified 230 V mains and he was concerned that usi a diode to drop power would cause flicker because of the 50Hz mains (maybe this was unreasonable but, with the large horsetail filiments, thermal time-constant could be very low.

The OP is wiring the system himself so he can configure the circuitry any way he wants.

Cheers

 

Did anyone mention making strings of two 40W bulbs in series. Then only 20W for each two bulb string string.

Ken

Yes, that was the option the OP decided to use.