Four Priests Brewery YouTube channel

[Agentgonzo]

I assume the fancy element power controller that Martin sent you works by pulsing the power on/off for the relay for longer/smaller amounts of time based on the potentiometer setting, rather than altering the actual voltage supply (ie, power) to the element?

 

[chopps]

A Quickie. The new tank has arrived.
Letting the driver take it back to the depot was not an option. Who hired the goon that loaded this through the curtainside on a ‘Tail Lift Only’ booking …

Four Priests Ep. 50 - Short Update - New Tank Day!

 

[chopps]

I assume the fancy element power controller that Martin sent you works by pulsing the power on/off for the relay for longer/smaller amounts of time based on the potentiometer setting, rather than altering the actual voltage supply (ie, power) to the element?

I think he did it the hard way. Pulsing is for SSR newbies, right @The-Engineer-That-Brews ?

 

[The-Engineer-That-Brews]

I think he did it the hard way. Pulsing is for SSR newbies, right @The-Engineer-That-Brews ?

Nope - pulsing on and off (for integer multiples of a mains cycle) is in fact the way to go for this kind of application, because it lets you only turn the heating element on or off when the mains voltage is zero... thus reducing both electromagnetic interference and 'shock loading' of the heating element which can otherwise give big surge currents that will shorten its life.

To be precise I use a technique called 'pulse density modulation', which I do with a variation on the 'Bresenham' algorithm that is more normally used to draw 'straight' lines on your computer screen out of discrete pixels (see Bresenham's line algorithm - Wikipedia)

For anyone who's interested, here is relevant section of my code. The main function repeatedly reads the position of the control knob and sets a global 'ones_count' as follows:

ones_count = (uint16_t)(0.5 + BRESENHAM_FRAME_SIZE * (float)adc_value / 1023.0);

Then on a 25Hz interval the following interrupt routine is called:

// interrupt service routine for Timer/Counter1, Output Compare A Match (TIM1_COMPA)
// updates the SSR pulse density modulator
//
ISR(TIMER1_COMPA_vect) {
static int16_t err;

err -= ones_count;

if (err < 0) {
err += BRESENHAM_FRAME_SIZE;
PORTB |= _BV(PB0); // SSR on
} else {
PORTB &= ~(_BV(PB0)); // SSR off
}

}

The 'BRESENHAM_FRAME_SIZE' is set to a suitably large prime number, to avoid predictable patterns in the on/off pulses.

 

[The-Engineer-That-Brews]

I think he did it the hard way. Pulsing is for SSR newbies, right @The-Engineer-That-Brews ?

This little video clip shows the overall effect: as the power increases the pattern changes from 'off', to mostly 'off' with a bit of 'on', to 50/50, to mostly 'on' with a bit of 'off', and then fully 'on'.
The video isn't great due to the strobing effect with the mains freq, but I think you can see what's happening.

 

[chopps]

Yeah thought so :)

 

[Chippy_Tea]

This little video clip shows the overall effect: as the power increases the pattern changes from 'off', to mostly 'off' with a bit of 'on', to 50/50, to mostly 'on' with a bit of 'off', and then fully 'on'.
The video isn't great due to the strobing effect with the mains freq, but I think you can see what's happening.

View attachment 71406

@The-Engineer-That-Brews i am not seeing a video.

 

[chopps]

@The-Engineer-That-Brews i am not seeing a video.

Are you not seeing this Chippy

 

[Chippy_Tea]

Are you not seeing this Chippy
View attachment 71488

This is what shows here Chrome on PC.
I can press the play button and the line goes across but nothing shows and there is no sound.

 

[Chippy_Tea]

If you are having the same playback problem please can you add your answer to the thread below not this one, thanks.

https://www.thehomebrewforum.co.uk/threads/video-playback.99439/

 

[Chippy_Tea]

 

[Chippy_Tea]

 

[Chippy_Tea]

 

[chopps]

 

[chopps]

Four Priests Ep. 55 - Brew Day! : Moston Dragon Bitter


Four Priests Ep. 56 - HarryBrew69 visits, and some inkbird stuff.


Four Priests Ep. 57 - Recipe trial and Retford news!


Four Priests Ep. 58 - Round Table Brew Day and more


Four Priests Ep. 59 - A New Beer, Friends come to visit, Crewe Beer Festival and more

 

[Chippy_Tea]

Sorry for putting a dampener on the post but have you considered getting a van if you have an accident in the car you are going to get crushed by those barrels and as it states below if caught overloaded fines are severe and you could go to prison.

What happens if a car is overloaded?​

All vehicles react differently to heavy loads and the penalties for breaking the law with an overloaded vehicle are severe, in some cases carrying a two year prison sentence.
Drive an overloaded car and it may well feel unsettled and behave in an unpredictable manner. As well as a reduction in stability, you will find steering and braking more difficult with slower responses to your steering inputs and crucial stopping distances lengthened.

https://www.carbuyer.co.uk/tips-and-advice/170624/overloaded-cars-how-much-can-you-safely-carry

 

[chopps]

Yes. I have thought about it a lot.

BMW X4M40d
Kerb weight 1860kg
Gross Weight 2560kg
My weight 102kg
Cask of ale 50kg

I can carry 11 casks if I could fit them in. I carry 7 and we drive slooooooowlllllyyy.

 

[Chippy_Tea]

I carry 7 and we drive slooooooowlllllyyy.

I am not trying to be a PITA but in my many years of driving trucks i have seen some bad stuff happen safe loading is big part of the job the weight the car can carry isn't really the issue you are driving with 350 Kg of unsecure load if you have to make an emergency stop you and your passenger will be crushed driving slowly is not going to stop that.

 

[Northern_Brewer]

you are driving with 350 Kg of unsecure load if you have to make an emergency stop you and your passenger will be crushed driving slowly is not going to stop that.

While your concern is understandable, as someone who has used various unconventional vehicles as drays - there's few formats I'd rather shift 350kg in than a full firkin. Their weight means they have a pretty high static friction so it's hard to shift them unless they tip on one side, and their "squatness" and being squeezed into a car means that tends not to happen. It's more of an issue when there's fewer of them so you have less weight, but they have more room to rattle around - but even when full I always use a strap to keep them under control. I've never worried about them moving under an emergency stop, it was always more a concern about the suspension and some nearby speed bumps.

Having said that @chopps - if your boot has a lightweight cover over a spare wheel bay or similar, that knackers pretty quickly, it would be worth at least getting some ply or chipboard to give more support, and maybe something to help the lip getting dinged - a camping mat or similar that you can flap out when you're un/loading.

 

[Scrattajack]

January 2023 and it's Four Priests delivery day.