An electronics question

[Andrew M]

Hi, am wondering if anyone knows enough about leccy stuff to advise please ?..

We have an HB Technik HiLo platform, it's the nature of the beast that it really should be powered "up" for 5 seconds before powering "down" after it's been left for any length of time. This is to ensure there is fluid pressure in all the rams, especially the ones that release a locking lever, before it attempts to lower the platform .

I know I can manually power up on the control button but is there any way of wiring in a control that will always automatically power up for that 5 secs before powering down, even if the operator has only hit the down button ? There are proximity sensors to show the system it is fully up so maybe these could be utilised so it only does my proposed "auto-up" when it's fully up rather than at any other point of operation ?

I'm just not that up to speed on this sort of electronic automation, but very willing to read and learn if there's any good suggestions on the plausibility of my idea.

Thanks,

 

[Mr Googler]

@vas will be along shortly ?

 

[kashurst]

The short answer is yes. However that is subject to a lot of caveats. It is also unlikely to be a DIY job unless you are a certain forumite known as Vas.
If there is a way to see the user manual and circuit diagrams let me know and I will see if I can think of anything.

 

[halcyon]

Hi, am wondering if anyone knows enough about leccy stuff to advise please ?..

We have an HB Technik HiLo platform, it's the nature of the beast that it really should be powered "up" for 5 seconds before powering "down" after it's been left for any length of time. This is to ensure there is fluid pressure in all the rams, especially the ones that release a locking lever, before it attempts to lower the platform .

I know I can manually power up on the control button but is there any way of wiring in a control that will always automatically power up for that 5 secs before powering down, even if the operator has only hit the down button ? There are proximity sensors to show the system it is fully up so maybe these could be utilised so it only does my proposed "auto-up" when it's fully up rather than at any other point of operation ?

I'm just not that up to speed on this sort of electronic automation, but very willing to read and learn if there's any good suggestions on the plausibility of my idea.

Thanks,

Check your insurance cover first, modifying a HiLo platform bit risky.

Brian

 

[julians]

it's the nature of the beast that it really should be powered "up" for 5 seconds before powering "down" after it's been left for any length of time. This is to ensure there is fluid pressure in all the rams, especially the ones that release a locking lever, before it attempts to lower the platform .

Does the manufacturer state that you should power it up for a few seconds before lowering if its been left? or are you possibly compensating for a fault that should really be fixed rather than creating a work around of powering up for a few seconds before down. - ie are the rams that slightly bleeding pressure off over time when they should just hold it.

 

[Hurricane]

My question is - WHY?
It isn't a big thing to do it manually and IMO, there are all kinds of dangers changing it to electronically do what you are asking.
If it had been a good thing to do. perhaps the manufacturers of the equipment would have already done this.
I build lots of electronic gizmos for our boat but I wouldn't build something like this.
Also most of my modifications are usually in parallel with the manufacturers systems so that they don't interfere with the basic design of the systems.

 

[jrudge]

You could - but I assume this is only the first use of the day. If it did it all the time and someone was trapped posing down would make it worse.

the older systems were easy to piggy back on. The switch was obvious. Now they communicate (sometimes ) by can bus etc which could make it complex.

I build stuff all the time but I would steer clear

 

[Andrew M]

Manty thanks for the replies and views , all good points and I get and accept any reasons to really consider what I'm looking at, to answer a few of the questions/doubts raised above :

Thanks, I'll find my user manual and circuits diags to look into the system operations.

Yes what I'm thinking of would only apply on the 1st use after any length of time, but also, mainly actually, to prevent any accidental or inadvertent push of the down button before the short up cycle. A cover over the switch panel might do the same for much less effort so is an option.

Yes, the manufacturer has advised that the system should be powered up in the manner described above before dropping the platform, one could then say it really should be/should have been built into the standard operation of the unit but it isn't so I'm looking to resolve that myself. In reality this is probably due to pressure bleeding off over time and the then need to restore that pressure before use, no fluid pressure is used to maintain the position of the platform once fully up, there are locking levers that mechanically do that, but they need to be raised by small rams to release the locking mechanism before the main rams can lower the platform,

I fully get the "someone might be trapped at half range" thing which is why I'm looking to see if the existing "fully up" proximity sensors could be used, if my theoretical "up" can only happen when the platform is fully up anyway then I can't see how it could be of any issue during normal operation, unless I'm not seeing the wood for the trees, and am very open to all suggestions and thoughts..

It may well be that I've started looking to do this, possibly unnecessarily, when there's other options to achieve the same, hence the request on it really, Thanks.

 

[vas]

since my name was mentioned...
I'd agree with previous posters, why not fix what seems not to be right?

But anyway, it's certainly doable and I'd first start by teeing on the high pressure pipework and fitting a decent wika analog gauge or danfoss -20mA sender (danfos as it's much chpear than others for high pressure ones when I was looking for one 3yrs ago). Monitor what's going on and figure a method that each time you press a button, system polls system pressure, if less than whatever value, then run pump to up the pressure. When pressure is right, then open whatever valve to move up or down.
Control theory (and application) is fairly simple and straightforward but as I said I'd first try to find out if by replacing some seals on the ram or whatnot you dont need all this complication.

cheers

V.

 

[penberth3]

.....Yes, the manufacturer has advised that the system should be powered up in the manner described above before dropping the platform, one could then say it really should be/should have been built into the standard operation of the unit but it isn't so I'm looking to resolve that myself.....

I think the manufacturer has got it right. I thought it was intuitive and plain common sense to take load off any locking mechanism before you release it. What do you do with your car steering lock, for example? I don't understand why this is a problem for you.

 

[Andrew M]

Thanks Vas, yes, I'll be looking at ram rebuilds when out the water this winter, and will get a gauge to investigate pipe pressures.

Penberth, fully agree with your comment. It's not however, as you suggest, a problem for me, I fully understand how to use it.... I think I mentioned in my post above that I am looking to cover off an accidental or inadvertent button press by someone other than me.

Thanks for the helpful comments all , I'll start with servicing the rams and the balancing valve over winter and see if I can remove any possible pressure loss.

 

[Mr Googler]

is there an on/off switch?

Maybe a timed relay could be added to run the motor up for 5 seconds whenever the system is turned on….assuming it doesn’t turn off when in use/ deployed

 

[Andrew M]

That's a point, the platform is energised once the "Aux" main breaker is turned on but I could easily have it run through a dedicated spare breaker switch on the main panel and do as you've suggested there. that might actually be the best solution as it would ensure the fluid pressure ( if it's dropped) is restored ready for correct operation. And would also isolate the platform switch from being operated accidentally if it's not switched on at the breaker, which would be the vast majority of the time as we only really use it to launch the tender. Excellent idea, thanks.

 

[st599]

since my name was mentioned...
I'd agree with previous posters, why not fix what seems not to be right?

But anyway, it's certainly doable and I'd first start by teeing on the high pressure pipework and fitting a decent wika analog gauge or danfoss -20mA sender (danfos as it's much chpear than others for high pressure ones when I was looking for one 3yrs ago). Monitor what's going on and figure a method that each time you press a button, system polls system pressure, if less than whatever value, then run pump to up the pressure. When pressure is right, then open whatever valve to move up or down.
Control theory (and application) is fairly simple and straightforward but as I said I'd first try to find out if by replacing some seals on the ram or whatnot you dont need all this complication.

cheers

V.

You'd also need to damp any hysteresis in the system and potentially deal with the edge cases of being at the end stops.