24V Relay circuit design

[Barton Bennett]

Good morning

Please could someone let me know if this is possible. I have a 24V hydraulic powerpack mounted on a truck, I need to Isolate it from inside the cab, and also isolate it from 4 of these optical sensors.

E2E-X8MB1TL12 2M | Omron Inductive Threaded Barrel Proximity Sensor, M12, 8 mm Detection, PNP NO, 10 → 30 V dc | RS

uk.rs-online.com

In other words, all 4 sensors need to be activated and the in-cab isolator switched on before the powerpack will switch on.

Is this possible using 1 relay? and can someone give me the easiest way to do this as a non-electrical minded person.

 

[KlausST]

Hi,

I have no idea what the situation is and what the question is.
A sketch - as always - tells more than a lot of words.
Does

need to Isolate it

mean "isolation" in an electrical manner?

Also you say "optical sensor" .... I don´t get it. Do you mean the linked sensor .. but it is in no way an "optical" one. Or are there other sensors.
I´m really lost.

Klaus

 

[danadakk]

When you say ISO do you mean simple on / off switching of the power pack
or real true "galvanic" isolation ?

https://www.monolithicpower.com/en/learning/mpscholar/isolation-solutions/intro-to-digital-isolation/of-isolation-techniques

Same question for sensors ?

If just switching power then one relay for powerpack with appropriate current and voltage ratings,
and for sensors just small signal relays as their V and I typically quite low.


Regards, Dana.

 

[Barton Bennett]

So, the 24V powerpack operates 4 hydraulic cylinders, that lift a box, the box is secured with container type twistlocks, these twistlocks need to be unlocked before the hydraulic system activates, so that they do not get torn off, the optical sensors sense that the twistlocks are open or closed.

24V powerpack needs to be electrically isolated unless the main switch in the cab is 'ON' and all 4 optical sensors are 'ON'
If any of the 5 are 'OFF' then the powerpack must not switch on

 

[Barton Bennett]

When you say ISO do you mean simple on / off switching of the power pack
or real true "galvanic" isolation ?

https://www.monolithicpower.com/en/learning/mpscholar/isolation-solutions/intro-to-digital-isolation/of-isolation-techniques

Same question for sensors ?

If just switching power then one relay for powerpack with appropriate current and voltage ratings,
and for sensors just small signal relays as their V and I typically quite low.


Regards, Dana.

I mean electrically isolate the powerpack. unless the switch and all 4 sensors (shown in link) allow the powerpack to get power

 

[BradtheRad]

all 4 sensors need to be activated and the in-cab isolator switched on before the powerpack will switch on.

The type of sensor is ambiguous. Have all types been tested (optical type versus inductive type)?.

There's the spec page calling the sensor inductive, normally Open and output type is PNP. Each sensor appears made to mount in a hole in the chassis (metal common ground of the vehicle). Conceivably a craftsman could custom-make a jig for mounting sensors exactly where each can do a proper job.

My reply was almost poised to recommend wiring all sensors in series and with any other switch. This one wire goes through the coil of your relay. However it may take extra work to wire the sensors in series. In any case all sensors' output wires (and other switch) ought to be assembled into some kind of logical 'AND' gate. Voltages must be compatible.

 

[Barton Bennett]

Hi,

I have no idea what the situation is and what the question is.
A sketch - as always - tells more than a lot of words.
Does

mean "isolation" in an electrical manner?

Also you say "optical sensor" .... I don´t get it. Do you mean the linked sensor .. but it is in no way an "optical" one. Or are there other sensors.
I´m really lost.

Klaus

Yes, sensor in the link, I'm not sure how it senses, that's why I linked it. there are 4 of them

--- Updated Sep 17, 2024 ---

The type of sensor is ambiguous. Have all types been tested (optical type versus inductive type)?.

There's the spec page calling the sensor inductive, normally Open and output type is PNP. Each sensor appears made to mount in a hole in the chassis (metal common ground of the vehicle). Conceivably a craftsman could custom-make a jig for mounting sensors exactly where each can do a proper job.

My reply was almost poised to recommend wiring all sensors in series and with any other switch. This one wire goes through the coil of your relay. However it may take extra work to wire the sensors in series. In any case all sensors' output wires (and other switch) ought to be assembled into some kind of logical 'AND' gate. Voltages must be compatible.

Hello Brad, please excuse my lack of electrical knowledge, we make truck bodies, with only basic electrics, this is why I attached the sensor that is fitted. I do not know how it senses, optically or inductively, or proximity. this is why I am asking for some help with a wiring diagram of how, if even possible to do

 

[danadakk]

This requires you sense the lack of pulses coming from sensor to determine its state. In addition, for safty sake,
detection sensor is operating and powered.

That is best suited for a micro or PLC based design with some software. Could be an all hardware design,
no software, but either case requires design work. Design would be simple, either case, but a consultant needed
I would advise.

And for safety/insurance purposes I would posit a licensed consultant in the field of transportation. Or just ignore
insurance considerations, you be the judge.

 

[Barton Bennett]

The type of sensor is ambiguous. Have all types been tested (optical type versus inductive type)?.

There's the spec page calling the sensor inductive, normally Open and output type is PNP. Each sensor appears made to mount in a hole in the chassis (metal common ground of the vehicle). Conceivably a craftsman could custom-make a jig for mounting sensors exactly where each can do a proper job.

My reply was almost poised to recommend wiring all sensors in series and with any other switch. This one wire goes through the coil of your relay. However it may take extra work to wire the sensors in series. In any case all sensors' output wires (and other switch) ought to be assembled into some kind of logical 'AND' gate. Voltages must be compatible.

Hello Brad, the extra wiring isnt a big issue, does this mean it is feasible to wire all 4 of these sensors in series together with the switch, to 1 x 24V relay in order to supply power tot he powerpack?

 

[BradtheRad]

Hello Brad, the extra wiring isnt a big issue, does this mean it is feasible to wire all 4 of these sensors in series together with the switch, to 1 x 24V relay in order to supply power tot he powerpack?

Yes, if you're lucky four sensors in series have little resistance and can pass sufficient voltage-current to energize your relay coil. Although the load-carrying contacts may be 24V rated, the coil contacts can have a different voltage range of activation.

Already several questions pop up. For one, detail of the twist lock mechanism. Example... size, easiest method to distinguish an unlocked mechanism. The cost at the inductive sensor link appears high, yet the mechanism might not even be massive enough to trigger the sensor. The sensor itself appears large and suited to detect a door.

 

[Barton Bennett]

Yes, if you're lucky four sensors in series have little resistance and can pass sufficient voltage-current to energize your relay coil. Although the load-carrying contacts may be 24V rated, the coil contacts can have a different voltage range of activation.

Already several questions pop up. For one, detail of the twist lock mechanism. Example... size, easiest method to distinguish an unlocked mechanism. The cost at the inductive sensor link appears high, yet the mechanism might not even be massive enough to trigger the sensor. The sensor itself appears large and suited to detect a door.

Hello Brad, ive left for the day, but will send some photos in the morning of the layout.