TC420/421

[aquatoid]

Hi @aquatoid, yes you are ok to provide the link. Marcel (@zozo) has asked for it and it is unlikely to conflict with forum rules. If the mods disagree, they'll delete the post. 🙂

Regards

Michael

Fair enough, here goes then, two examples in fact:
https://www.jooksy.com/products/tc4...widely-used-in-aquariums-fish-tank-plant-grow
https://www.aliexpress.com/item/TC4...636.html?spm=a2g0s.9042311.0.0.27424c4d2VsxFc

As I'm no electrician I have no idea how these Volt and Amp ratings are defined. As a layman (with some ancient physics background) I'd assume the problem would be heat. So connecting a cable with larger conductor to a cable with smaller conductor could either a) cause smoke and flames or b) throttle the current to the lower standard.

I've been looking into all sorts of plugs and jacks lately, and there are all kinds of combinations possible. As I earlier mentioned the AC/DC converter I'm looking at is rated 13 A @ 12 V, yet I have not been able to find a jack that is rated high enough for current. There are jacks with 36 V rating and higher Amp ratings than 12 V jacks. Could I plug 13 A @ 12 V plug into a X A @ 36 V jack as long as the wattage is the same, as in

13 A * 12 V = 156 W = X A * 36 V
=> X A = 156 W / 36 V = 4,5 A (rounded up)

All I want is not to burn my home. This project has taught me quite a bit about wires and AWG stuff, but there is still so much to learn...

 

[zozo]

As far as i know you can use both power inputs for total load as long as the PSU is up to the task.. Never did read it anywhere before that it should be different. Tho must say it's only theoretical, personaly i never used the DC jack input, always connected via the screw connectors for convenience and to have a more secured connection. A dc plug can be pulled out by mistake wihtout notice..

Personaly i rather like to connect the TC like this.


Anyway i can imagine your worries and it is rather strange they describe only small load without providing real numbers.

if you want to get to the bottom of the story than contact

http://www.worlduniqueen.com/support.aspx?typeid=15

They are the original TC420/21/23 developers they definitively know the correct answer. 🙂

 

[aquatoid]

I'll ask them for sure, thank you for linking that website.

One thing about those screw connectors worries me too. They look like a perfect way to fry yourself or your cat. How dangerous is operating this device? At least I see no way they would not have a voltage on them. Seems I have more questions to ask the devs.

 

[zozo]

I'll ask them for sure, thank you for linking that website.

One thing about those screw connectors worries me too. They look like a perfect way to fry yourself or your cat. How dangerous is operating this device? At least I see no way they would not have a voltage on them. Seems I have more questions to ask the devs.

At 12 volts there aint much to fry, it is pretty safe to use.. Hang it to the wall or inside the cabinet.. Unprotected connectors laying around in the open to be touched or risking to spill water, coffe whatever on it is never a good idea.

But any AC/DC PSU nowadays comes with a buildin surge protector, this means as soon as it short cuts it should switch off and needs a hard reboot to start up again. (Meaning unplug and replug to the mains). If the PSU doesn't do this, than its failry outdated for decades and shouldn't be used anymore.
ALso if the PSu is over powered it will shut off before it gets to hot, an very early sign is flickering lights long before it switches off.

But the TC on the other hand, if the cat shortcuts the Channel and V+ it will fry the mosfet and the channel becomes unusable. Thus however it is conneted via screw or plug, it still should be out of direct reach from anything touching it.

Use those fork connectors as shown in the picture, much easier to work with than naked cable ends.

 

[aquatoid]

Now that I have received my own TC421 I can see that even in the "official manual"/leaflet in the box the DC jack is described in exactly the same way, only for "small loads". So far no answer from the developers though...

 

[zozo]

Now that I have received my own TC421 I can see that even in the "official manual"/leaflet in the box the DC jack is described in exactly the same way, only for "small loads". So far no answer from the developers though...

Must be an update than, maybe after some negative feedback about it.. My first TC i've bought was about 5 or 6 years ago. Don't remember it saying that. Bought a few others after that but didn't feel the need to reread the manual. Good thing i never used the plug for mains...

I also have no idea what is considered a small load and at what point it's getting high.

Tho the channels are rated in Amps.. And 4 amps per channel @ 12 violt is 48 watt LED light.. And that is actualy a lot of LED light already. My best guess for aqaurium use you must have a pretty large high tech tank to get to the high end of the device with light requirment.

If you use 50 watt devided over 5 channels, that's 10 watt per channel, you would pull 1/5, a bit over 20% of it's full capacity. But if they don't give a number i'm not sure if that can be considered small.

Ask the seller you bought it from. If its ebay or aliexpress, they rely mainly on positive feedback and usualy always answer swiftly to solve issues. Thus they don't want you to write negative feedback. And such distracting statement in the manual is defitively a future negative feedback trigger.

 

[aquatoid]

They actually have responded now. It seems the Facebook thing on their website was not really functioning too well. Or perhaps I just failed with it since Facebook really isn't something I generally use.

Sent an email today and got a reply today. And the DC plug is rated for 6 Amps only. Definitely a necessary thing to write with actual numbers instead of vague words. With that 16+ Amp converter with a DC plug I might have seen some smoke signals from the device. By my calculations I will be drawing more than that for sure. Replacing 4 x 36W fluorescent tubes.

 

[zozo]

And the DC plug is rated for 6 Amps only. Definitely a necessary thing to write with actual numbers instead of vague words.

Indeed vague..

With that 16+ Amp converter with a DC plug I might have seen some smoke signals from the device. By my calculations I will be drawing more than that for sure. Replacing 4 x 36W fluorescent tubes.

With what are you replacing the fluorescent tubes?

16 amp power supply doesn't tell me what you are actualy consumming.. 🙂 A 16 amp rated PSU can deliver up to 16 amp it only gives what you ask as long as it stays bellow 16 Amp.

You need to add all the lights in wattage.. And there is where lots of people get distracted.

As described above, the PSU and the TC is rated in amps, but the lights are mainly rated in Watts.. Than you need to convert Watts to Amps to know how much the PSU is drawing through the TC.

For example if the lights you run all together draw 60 Watt @ 12 Volt than you need to devide Watt by Volt as 60/12= 5 amps

Than again if you want to know how many watts can i draw with 6 amp.. Multiply Volt x Amp in this case 6 x 12 = 72 Watt.

🙂

 

[aquatoid]

I based my calculations on this website: https://www.tc420.net/choosing-LEDs-for-your-aquarium.php

I'll be using 5630 LED strips. Based on the lumen values on the tubes I'm replacing the site suggested something that equates to 3 channels each having a 36 W load. Plus a night light in the 4th channel which won't be on with the others. And seeing how the PSU vendors suggest having 20% extra margin on top of the max load when you are selecting the wattage of the PSU, 150 W PSU is realistically a minimum for me. Assuming of course that I need that many LEDs. This is my first DIY light system, so I have no previous experience to lean on.

I already have the LEDs (thanks China), and I went for a collection of warm white, cold white, blue and red ones. The plan as of now is to have 3 x warm white, 3 x cold white, 3 x blue and 1 x red strip bits (each with 3 LEDs) in one unit. Each channel would have 3 units so 9 in total.

To be fair, I might still go for a 200 W PSU just to be safe, so it runs cooler and has better tolerances should my plans get more grandiose along the way. I'd rather be safe than sorry. Even got me some 16 AWG wire for the main line running through the lamp so it can take the maximum current each channel can output without going up in smoke. At least it should be 16 AWG, it just has no markings on it... While I was at it I also got some 18 AWG DC extension cords with plugs, so i can rig a fast plug system for the lights.

I have plans, I just hope some of them work in practice...

 

[zozo]

Succes!.. Sounds good.. 🙂

Tho might add the tc420.net blog is ok and technicaly a great guide but rather outdated regarding specified led types..

Example: he states

5630 are the newest and brightest LEDs currently available on strips.

But that is at the time of writing, i guess that might be pre 2014 and mean while much beter SMD leds have been developed giving alot more light at same consumption. Something like the SMD8520 Dual chip launched 2017. Is a smaller led with 65 lumen per led and 72 leds per metre and +/- 4500 lumen at 18 watt
That rather a lot of light for an aqaurium.. 🙂 And the 5630 doesn't even come close to that.

The author realy should update his site with statements about newest and brightest currently available. That's distracting and simply not accurate.

 

[aquatoid]

I am still building my system, slowly but hopefully surely, and now I am working on the TC421 setup.

One thing started nagging at the back of my head. When I set a channel to 100%, does that mean the device is pushing 4 Amps down that line no matter the load. So one LED would be really bright and hot for a really short while and then just burn out. Do I need to do more maths to calculate the nominal 100% for my load and then see what fraction that is of 4 Amps and use that percentage as the "100%" value in the controller software?

Like I've said before, I am no electrician, so I might have gotten all this very wrong, but it would be handy to know so I won't overload my LEDs and burn them out ahead of time.

 

[zozo]

I am still building my system, slowly but hopefully surely, and now I am working on the TC421 setup.

One thing started nagging at the back of my head. When I set a channel to 100%, does that mean the device is pushing 4 Amps down that line no matter the load. So one LED would be really bright and hot for a really short while and then just burn out. Do I need to do more maths to calculate the nominal 100% for my load and then see what fraction that is of 4 Amps and use that percentage as the "100%" value in the controller software?

Like I've said before, I am no electrician, so I might have gotten all this very wrong, but it would be handy to know so I won't overload my LEDs and burn them out ahead of time.

No it doesn't.. 🙂 Depending on the LED wattage.. The conversion is quite easy to make with this formula.

Volt x Amp = Watt

Example:

12 volt x 4 Amp = 48 Watt.. Means 1 channel can take 48 watt LED at 100%

If your LED consumes according specs 20 Watt at 12 volt (100%)

than

W / V = A makes 20 Watt / 12 volt = 1,6 Amps load on the channel

 

[aquatoid]

No it doesn't.. 🙂 Depending on the LED wattage.. The conversion is quite easy to make with this formula.

Volt x Amp = Watt

Example:

12 volt x 4 Amp = 48 Watt.. Means 1 channel can take 48 watt LED at 100%

If your LED consumes according specs 20 Watt at 12 volt (100%)

than

W / V = A makes 20 Watt / 12 volt = 1,6 Amps load on the channel

I'm a bit sceptical here, but I do appreciate the answer. I know that constant voltage power supplies dish out just what the circuit needs, and my power supply is one of those. My problem is (comprehending) how the TC-unit determines the actual load on the channel and then adjusts that to the percentage defined by the user. By my logic the device could now be acting as a constant current supply overriding the actual power supplies regulation.

I'd really like to understand the deeper workings here, so I can trust what I'm doing. Sadly I don't (yet) have an ammeter at hand, so I can't make my own measurements.

(As much as load needs to run) x (% defined by user) < 4 Amps

or

4 Amps x % defined by user

https://electronics.stackexchange.c...-current-than-what-the-component-is-rated-for
Quote from that thread:
"
To answer the title of your question, the answer is no. It is not ok to supply more current to a component than its rated value.

However, it is ok to have a voltage power supply rated for more current than the components rated value because the component will draw as much as it needs. If you are pushing more current into (forcefully) the component, then the component will exceed its rated value, heat up and be destroyed. Such as if you use a constant current source or you use a large voltage (which will cause more current to flow). But if you use the rated voltage, then the load will only take what is required, regardless of how much current is available to be drawn from the source.
"

 

[zozo]

I'm not sure what you are trying to do here.. 🙂 The TC controller is intended to work only with constant voltage setups at DCV12 or DCV24..

If you are using a LED that requires constant current i'm afraid the TC controller is not for you without DIYing its circuit..

Constant voltage is pretty straight foreward as stated in my previous answer..

Read this, it explains.. Tho mind the circuits given don't seem to apply for the TC421.. Something changed, not yet documented.
https://www.tc420.net/

 

[aquatoid]

Thank you, that PWM part was what was fuzzy for me even though I knew about that website. I just was thinking it would be the strength of DC current that does the dimming and brightening. And that TC while forcing a current would act as a constant current "PSU" unless some more calculations are done. I do not want constant current, I was worried about it!

I'm just "a bit" nervous about screwing up...

https://www.eetimes.com/document.asp?doc_id=1281013#
"LEDs can be dimmed in two ways: analog and pulse-width modulation (PWM) dimming. Analog dimming changes LED light output by simply adjusting the DC current in the string, while PWM dimming achieves the same effect by varying the duty cycle of a constant current in the string to effectively change the average current in the string. Despite its attractive simplicity, analog dimming is inappropriate for many applications."

 

[zozo]

I can imagine it is distracting all with Watts and Amps and constant current or constant voltage.. But with a DCV12 or DCV24 constant voltage led module/strip nothing much can go wrong.

In the end all leds require a constant current since all are the same, its a diode. The constant current in this case is provided by the current sense resistor on the module. That little black block on the strip for each set of 3 leds is the current sense resistor.

As said if you connect a 12 volt led strip that consumes 48 watt than the load on the TC channel is 4 amp current total. Dimming it wont change that, since PWM is pulse modulating switching the led on/off in high frequency at the cathode (negative lead) not affecting the current nor the voltage.

 

[Jibber]

Great thread as i've been looking into one of these controllers for a while now. I've now brought a TC421 with the intention of using it to control a couple of solenoid valves. I've set it all up and connected it but I've got a couple of problems. 1st is how do you change from fade to jump as i just need to open and close the solenoids and i'm not sure if the delay in ramping the voltage up will cause any damage. 2nd is i only get 15v at the output terminals, i'm using a 24v power supply and I've checked the input voltage on the v- and v+ terminals and it's 24.03v but i only ever get 15.3v between the v+ and Ch1 terminals. any help much appreciated. Thanks James

 

[zozo]

I'm not sure the TC421 has a jump setting, at least it does not show in its default PLed software version 2.2..
http://www.worlduniqueen.com/support_list.aspx?id=192&type=1&typeid=15

Drop the above website a line and ask if there are alternatives.. They are the TC developers..

Tho the TC420 Pled 2.1 does have this jump setting by default, now i'm not sure if this software works on the TC421 connected via USB.
That might be worth a try, depends on the chips extension configuration.. If both use same file extension or the update TC421 chip recognizes TC420 file exteinsion you're good to go. But probably will loose the WIFI ability..

The Wifi feature anyway is a bit of a strange only partialy functioning feature that doesn't realy add much to it.. You can only add schedules via Wifi but if you want to set a new schedule you still have to do this physicaly at the divice using its buttons.

Thus in your case using teh TC421 for other purpose than LED controlling is a bit of ??? What shall i say.. Not the best choice anyway.. I lately purchased a TC421 for a friend, installed it and found out it actualy is a waste of money regarding the extra near useless wifi feature.. Simply badly presale documented, if it was documeted fully never would have bought it..

If the earlier Pled version doesn't work in the TC421 you most likely did the wrong investment and need to purchase a TC420.. Or see if you can arrange a swap with the vendor..

 

[rebel]

Great thread as i've been looking into one of these controllers for a while now. I've now brought a TC421 with the intention of using it to control a couple of solenoid valves. I've set it all up and connected it but I've got a couple of problems. 1st is how do you change from fade to jump as i just need to open and close the solenoids and i'm not sure if the delay in ramping the voltage up will cause any damage. 2nd is i only get 15v at the output terminals, i'm using a 24v power supply and I've checked the input voltage on the v- and v+ terminals and it's 24.03v but i only ever get 15.3v between the v+ and Ch1 terminals. any help much appreciated. Thanks James

How about the other channels? Do they give you 24V? Maybe defective channel.

 

[Jibber]

good thinking rebel .Just tested it and they all seem to be outputting 23.9v now so must have been a glitch in the Matrix ! thanks for the suggestion tho