DC to DC Converter

[Onoff]

I need to drop 24VDC to 4.5VDC, replacing 3 x 1.5V batteries. Are these cheap DC to DC modules safe, as in left on 24/7?

XL4015 DC-DC 5A Adjustable Step Down Power Supply Module 4-38V

The XL4015 is a DC to DC adjustable step down power supply module featuring high power and excellent efficiency. The module can be used as a charger for various batteries and features overcurrent protection capabilities. Input voltage range: 4-38VDC Output voltage range: 1.25-36VDC Output...

www.switchelectronics.co.uk

Will print a holder for it and it'll sit inside the gate control box where I have 24VDC available.

https://flic.kr/p/2q8K9d2

 

[sako243]

That particular module (chip rather than that specific variation) I've used without bother.

Also note that most gate control boards don't provide a huge amount of power on those 24V supply rails. They are usually only for sensors etc. You'd need to check the manual of the particular board to see how much you can pull.

 

[Red'n'Black]

The photo shows a heatsink, are you supposed to glue that onto the regulator IC yourself?

If you're only using a fraction of the 5A rating it should be OK in an enclosed box (looks like the box is IP67 so no issues there) with no ventilation.

If you're planning to pull the full 5A out of it I'd mock it up on the bench first and see how hot it gets.

 

[Onoff]

That particular module (chip rather than that specific variation) I've used without bother.

Also note that most gate control boards don't provide a huge amount of power on those 24V supply rails. They are usually only for sensors etc. You'd need to check the manual of the particular board to see how much you can pull.

Manual is a bit sparse on info / conflicting as already proven. 24VAC at 0.5A it would appear available. As there's an AC symbol next to it, presumably from 11?

I've already tapped off 24VAC from 11 to power my timer relay. 13 feeds 24VDC to the flashing beacon but only when the gate is opening.

I wonder if it's another manual typo and it's actually 24VDC at 0.5A from 14-15.

 

[sako243]

My experience is you can draw sod all from these additional outputs. To be honest it's probably easier to tap off the mains coming in and have a dedicated AC/DC converter. RS stock a load that aren't that dear maybe about a tenner.

I can't remember the brand but possible Traco or Meanwell do some nice sealed panel mount ones with screw terminals. They're in a black box. If I remember I'll try and find a link or the part number for it.

 

[ajlelectronics]

It looks to me like 14 & 15 are the DC output from the PSU at 24V. You could certainly tap off there.

 

[Onoff]

To be honest it's probably easier to tap off the mains coming in

That reminds me, I need to get a trace heating cable to run up inside the gate track for the winter!

https://flic.kr/p/nv3bDb

 

[Robotstar5]

That reminds me, I need to get a trace heating cable to run up inside the gate track for the winter!

This any good? 240V x 100W x 3 metres long and British made!

 

[Onoff]

This any good? 240V x 100W x 3 metres long and British made!

View attachment 460632

Maybe, let me have a measure up. Thanks.

 

[Onoff]

This any good? 240V x 100W x 3 metres long and British made!

View attachment 460632

Daft question has this got an inbuilt thermostat or does it just stay on?

 

[Onoff]

The photo shows a heatsink, are you supposed to glue that onto the regulator IC yourself?

If you're only using a fraction of the 5A rating it should be OK in an enclosed box (looks like the box is IP67 so no issues there) with no ventilation.

If you're planning to pull the full 5A out of it I'd mock it up on the bench first and see how hot it gets.

I just want to power a PIR alarm that usually runs on 3 x 1.5V AAAs

 

[Red'n'Black]

I just want to power a PIR alarm that usually runs on 3 x 1.5V AAAs

OK, anything that's meant to be permanently powered by AAAs won't stress it at all. We're probably taking microamps not amps.

 

[Robotstar5]

Daft question has this got an inbuilt thermostat or does it just stay on?

No it doesn't have a built-in thermostat so best to control it with an external frost stat, I'm not sure if it's the self-regulating type.

 

[Onoff]

No it doesn't have a built-in thermostat so best to control it with an external frost stat, I'm not sure if it's the self-regulating type.

View attachment 460732

View attachment 460733

Apologies taking so long to get to get back to you. I'm not sure 3m is long enough. Power would be from the lhs pillar, connections about 1m above ground. I'm going to get another metre of rail and fill in from the pillar to the existing. Mainly just to house / protect the trace heating.

At the mo there's x2 3m tracks. The tape is out to 3m from where the tape starts. The heated length then needs to be about 6m so as to encompass the length where both wheels roll.

Video clip. (Not finished btw):

https://flic.kr/p/2q9QD2W

Thanks anyway.

 

[Robotstar5]

Just seen your other post about making gates operate safely, I still have a few safety relays, positively guided contact relays and safety contactors if you need any, mainly 24VDC kit plus a few 24VDC PSU's.
The by products of too many years of panel building

 

[Onoff]

Just seen your other post about making gates operate safely, I still have a few safety relays, positively guided contact relays and safety contactors if you need any, mainly 24VDC kit plus a few 24VDC PSU's.
The by products of too many years of panel building

Yes, I'm about to ignore that post/ member. Not got the time to argue.

This extract from the manual is basically my set up:

"6" are the suggested contact strips. I'm wanting one on the lhs pillar hard wired back to the control box "2". Then one each end of the gate. These will need to be wireless. I think I can get a single, wireless transmitter that will take both safety strips input. Then I need a receiver to fit in the control box.

I need to talk to a supplier.

I'll likely not fit a strip on the rhs pillar. The gate is basically smooth. Tba on that one. It would likely need to be wireless as well.

 

[Robotstar5]

I can't see why they have safety edges on each pillar, you would just need one on the leading edge of the gate, guessing "4" is photocells?, which from what i can recall of machine guarding would be at 300mm & 600mm above ground level.

 

[Onoff]

I can't see why they have safety edges on each pillar, you would just need one on the leading edge of the gate, guessing "4" is photocells?, which from what i can recall of machine guarding would be at 300mm & 600mm above ground level.

If just on the gate then I'd need it right on the edge to avoid the scissor action against the brick pillar edge. The gate is quite deep. I'll likely put a solid board all the way up. Probably black uPVC.

https://flic.kr/p/nwXoam

https://flic.kr/p/nDZxaW

https://flic.kr/p/nFMKPp

Not sure how old these EU directives are:

I strapped a cheap spring balance on a rope and let the gate stop against it. Not very scientific but seems to stop at somewhere around 27kg.