The multimeter should be set to DC Volts, not AC. The range should be the next higher one than 24.

Do you know how to measure current?

I don't know! :-/
When I did DC nothing seemed to happen! No stable numbers, zeroes or minuses.
Even with no wire pot is still sparking and smelling of burn. Should I just give up on this power source and find another?

PS shiny new multimeter now! Pic attached. I used the first setting from the left.

 

@Bernard @djsfantasi

DJS Fantasi you said in another post that maybe I THINK I'm doing something, I think that something is an R2. I've been very blind and overlooked it completely, I've soldered onto the POT but not understood what the R2 is. What is it? Is it something I need to buy? Not sure I got it with the kit.

 

Hello,

I see that it has separate AC and DC voltage ranges, but on the current ranges you must select AC or DC with the function knob.



Bertus

 

For R1 sparking could be Q1 C & B shorted internally from past power reversal?
Next step would , NO power to board, remove leads from R1, pot & check resistance on outer 2 pins to see if resistance is still about 5,000 ohms, 5k, then check from left pin to center, rotate pot
resistance should go from 0 to 5k. If pot is still good I'll mail you new transistors & 9.1k resistor , no charge if you will PM, private message, to me your address.

 

First, when you tested the red strip before, did you temporarily hook it up the the pump power supply? If so, repeat that test to ensure the red strip hasn’t been damaged. And repeat the test for the white strip as well for the same reason.

One reason the white strip no longer works MAY be that it’s leads are reversed. Don’t just swap them; visually ensure they are correct. The black wire on the strip should go to the negative connection of power.

I am not sure why Bernard included R2. I can guess a couple of reasons to myself, but I’d include it.

Wiring should be straightforward. But you need to check a few things. The voltages must match. A difference of less than 1/2V wont make a difference. The polarity, plus and minus, must match. And the available current (from a power supply) must be greater than the current required. This last point is why I asked if you knew how to measure the current. I’m not familiar with your multimeter, I'd try to explain how. I’d like a measurement of the current required for each strip, if someone familiar with the meter can help.

 

For R1 sparking could be Q1 C & B shorted internally from past power reversal?
Next step would , NO power to board, remove leads from R1, pot & check resistance on outer 2 pins to see if resistance is still about 5,000 ohms, 5k, then check from left pin to center, rotate pot
resistance should go from 0 to 5k. If pot is still good I'll mail you new transistors & 9.1k resistor , no charge if you will PM, private message, to me your address.

Thanks Bernard going to do all this and get back to you tomorrow. I have another POT so if it's out then I can replace it but I'll take the other stuff thanks but let me see what is working and get back to you.

 

First, when you tested the red strip before, did you temporarily hook it up the the pump power supply? If so, repeat that test to ensure the red strip hasn’t been damaged. And repeat the test for the white strip as well for the same reason.

One reason the white strip no longer works MAY be that it’s leads are reversed. Don’t just swap them; visually ensure they are correct. The black wire on the strip should go to the negative connection of power.

I am not sure why Bernard included R2. I can guess a couple of reasons to myself, but I’d include it.

Wiring should be straightforward. But you need to check a few things. The voltages must match. A difference of less than 1/2V wont make a difference. The polarity, plus and minus, must match. And the available current (from a power supply) must be greater than the current required. This last point is why I asked if you knew how to measure the current. I’m not familiar with your multimeter, I'd try to explain how. I’d like a measurement of the current required for each strip, if someone familiar with the meter can help.

White lead works just only when the POT is on and that's not what it's meant to do. Long story short I think I need to just take the bits out and start again. I think the lack of resistor is why the red light has been flashing and I think I've messed up the POT.
Question about the voltage, if the voltage I am supplying is 24V should that be a problem at all? I just don't get why the white light is cool with the voltage supplied but the red isn't.

 

Thanks Bernard going to do all this and get back to you tomorrow. I have another POT so if it's out then I can replace it but I'll take the other stuff thanks but let me see what is working and get back to you.

Bernard, let's keep it simple and move quickly, I have spares I'll take it all out and start again with a fresh everything and better soldering. Sent you links for products, quicker for me to buy it here. You're in the US right?

 

Two darlington transistors, D1326, resistor & a bit of wire is still under 1 oz. so postage is just US $ 1.20.
Spare pot might be 50k but will work with my transistors but I may check.
Did check, works fine; pot a little erratic from non use but a 10 uF cap., wiper to - cleared up the bit of flicker.
Some ref. to R2: P2 # 25, P3 # 52, P4 #64, 66, 69.
Tucson, Arizona, USA.

 

I thought that I had sent a PM, personal message, a few days ago but can find no trace of it now.
In process of looking for conversations, inaverntaly ( SP ?) switched avatar. Half head = me about 1938, Life Mag. camp for NY,NY under privileged kids.

 

I thought that I had sent a PM, personal message, a few days ago but can find no trace of it now.
In process of looking for conversations, inaverntaly ( SP ?) switched avatar. Half head = me about 1938, Life Mag. camp for NY,NY under privileged kids.

Amazing Bernard. I replied to you. Should I write again?

 

Lili, message not received, I'm waiting for an answer from moderator on PM problem.

 

Lilli, now that Bernard is back, I’m not ghosting you. Just stepping back so I won’t confuse the issues

 

@disfantasi, I did not know that I was gone, just lost PM- conversation capability, seems to be gone. Any suggestions?

 

Lilli, now that Bernard is back, I’m not ghosting you. Just stepping back so I won’t confuse the issues

No worries, thanks a mill for all you've done.

 

Lili, did the 5k pot survive? A 50k pot might give poor results with a TIP120 as input Z around 8k
where as my D1326 input Z around 100k, so 50k pot is fine.
I've gained a 1/2 of a head. Andrew, the tall fellow, was my body guard.

 

Good morning Lilli, note that I changed my avatar again to beer can A10 Warthog.
A letter is on the way with 2 D1326 darlington transistors, 82k resistor with leads, a bit of heat shrink & wire. Woops, 9.1k & 10 uF cap. still on bench but I'm assuming that you are going to use 50k pot. Note that no insulating washers are needed between Q1 & HS. A hand full of D1326's were salvaged from equipment accounting for the clipped leads.

 

Good morning Lilli, note that I changed my avatar again to beer can A10 Warthog.
A letter is on the way with 2 D1326 darlington transistors, 82k resistor with leads, a bit of heat shrink & wire. Woops, 9.1k & 10 uF cap. still on bench but I'm assuming that you are going to use 50k pot. Note that no insulating washers are needed between Q1 & HS. A hand full of D1326's were salvaged from equipment accounting for the clipped leads.

If I use the 50k do I not need the resistor? I don't knew what a 10uF is.

 

With resistor, dimming takes place over full rotation of pot.
Micro symbol does not appear on my keyboard so I use u. A farad capacitor is a lot of capacity so divide it by 1,000,000 then multiply by 10
to get 10 uF. Cap. is surface mount with added leads, about 3 mm X 3 mm X 2 mm, non polarized so that it cannot be connected backwards. If pot pin 2 , wiper, output is electrically smooth then C not needed.

 

Lilli, has the letter arrived yet, sees like a week should do ?