New Hob - power supply

[Mike Adams]

I have just purchased a replacement Hob from Midland C and it comes with a 240v ignition system. As I don't have 240v around the boat I was thinking of powering it through a small inverter from the 12v supply. I can't find any details of the power consumption but I assume it is quite small and only draws power when in use. Anyone done this? I was going to look for an inverter with zero or low power draw on standby or I can just switch it on when needed otherwise it is back to the lighter.

[john6767]

Can’t you just replace the ignition with a stand-alone 12V one

[Jen-in-Wellies]

https://www.midlandchandlers.co.uk/products/ignition-conversion-kit-12v-gc-154

No idea if this is compatible with the hob you've bought. Not done this conversion, but it can be done on at least some cookers.

Jen

[nicknorman]

I think getting a small inverter is the best option. The power consumption will be very low. I’d sound a note of caution about the  idea of replacing the ignition system with a 12v one:

 

In the old days, flame failure device (aka flame supervision) worked with either a thermocouple or even a pressure bulb. The trouble with those systems is that you have to hold the gas knob down for a few seconds whilst the sensor heats up. Some modern cookers therefore use electronic flame supervision - there is no thermocouple, and often the ignition electrode doubles as a flame sensing electrode. It detects the flame virtually instantly. So there is a bit of electronics in there, linked to the gas valves. So for those types, they need a power supply all the time the burner is on, and they are expecting mains voltage to power it.

 

If you can see a thermocouple poking out adjacent to the burners, it is the “old fashioned” type but if there is just an electrode, it is the modern type.

Edited May 12, 2020 by nicknorman

[john6767]

5 minutes ago, nicknorman said:

I think getting a small inverter is the best option. The power consumption will be very low. I’d sound a note of caution about the  idea of replacing the ignition system with a 12v one:

 

In the old days, flame failure device (aka flame supervision) worked with either a thermocouple or even a pressure bulb. The trouble with those systems is that you have to hold the gas knob down for a few seconds whilst the sensor heats up. Some modern cookers therefore use electronic flame supervision - there is no thermocouple, and often the ignition electrode doubles as a flame sensing electrode. It detects the flame virtually instantly. So there is a bit of electronics in there, linked to the gas valves. So for those types, they need a power supply all the time the burner is on, and they are expecting mains voltage to power it.

 

If you can see a thermocouple poking out adjacent to the burners, it is the “old fashioned” type but if there is just an electrode, it is the modern type.

I wasn’t aware of that, so as you say not to be messed with if it is that type.  We have a 12V Ingition unit similar to the above, but the flame failure is just thermocouples.

[Ex Brummie]

At £23.90, a small inverter will be much cheaper. Some years ago, on a hire cruiser in Ireland, the cooker ignition was supplied with power from a 75watt inverter that plugged in to a lighter type socket. If you don't want the power all the time, then put a switch into the circuit.

[Mike Adams]

I’ve just been down to the bottom of the garden to have a look. It is 'old school' with thermocouples and ceramic igniters so at least I can manually light it. It looks impossible to access the spark generating unit without dismantling the whole thing, and as it is new and yet unused, maybe not a good idea. I will have go at measuring the 240v demand current and test it on an inverter first. What I need a a simple inverter that doesn't take power unless there is a load on it. Thanks for the help; I will check with MC in case the spark unit can be easily changed for a 12v one.

[WotEver]

25 minutes ago, Mike Adams said:

What I need a a simple inverter that doesn't take power unless there is a load on it.

Or a simple switch next to the hob.  Turn it on when you require the igniters, turn it off afterwards. Fit an indicator light to know when it's on.

[GUMPY]

https://www.ebay.co.uk/itm/293181504315

Quick, simple and cheap.

[ditchcrawler]

1 hour ago, Mike Adams said:

I’ve just been down to the bottom of the garden to have a look. It is 'old school' with thermocouples and ceramic igniters so at least I can manually light it. It looks impossible to access the spark generating unit without dismantling the whole thing, and as it is new and yet unused, maybe not a good idea. I will have go at measuring the 240v demand current and test it on an inverter first. What I need a a simple inverter that doesn't take power unless there is a load on it. Thanks for the help; I will check with MC in case the spark unit can be easily changed for a 12v one.

 

ALL inverters use power if they are switched on, load or no load

20 minutes ago, Loddon said:

https://www.ebay.co.uk/itm/293181504315

Quick, simple and cheap.

They even work on diesel cookers

 

[Jen-in-Wellies]

1 hour ago, Mike Adams said:

What I need a a simple inverter that doesn't take power unless there is a load on it.

It is the more complicated and expensive inverters that take the least power with no load. Easiest is @WotEver's suggestion of a switch and an indicator light. in the 12V input to a small cheapo inverter and switch off when you aren't cooking mount the switch close to the cooker and in your eye line and you'll soon get used to turning it on and off. So much so that you'll be looking for the switch when using another cooker somewhere else ?. In the same way that I look for the whale gulper switch when taking a shower in houses and hotel rooms and forget to put the plug in when running a bath.

Something like https://www.12voltplanet.co.uk/waterproof-onoff-rectangular-marine-rocker-switch-with-red-illumination-12v-24v.html maybe. Able to handle 10A, so plenty for a small inverter.

 

[Detling]

Beware of any inverters 'no load' current, I have a 300 watt one for the car that takes just over 1 amp with no load, use a switch, you could use one of those push in light switches which take a minute or so to switch off, use a relay to power the inverter and the push switch powers the relay.

[Mike Adams]

I've tested it and it works from a small inverter. For now I think I will stick with the 99p lighter as the boss is happy with that and the simple job of changing the hob has taken over a day what with cutting a  bigger hole, changing the pipework, moving the drawer down a bit, epoxying the new cut out so it doesn't get damp, repainting inside the cupboard and so on!

[ditchcrawler]

3 hours ago, Jen-in-Wellies said:

It is the more complicated and expensive inverters that take the least power with no load. Easiest is @WotEver's suggestion of a switch and an indicator light. in the 12V input to a small cheapo inverter and switch off when you aren't cooking mount the switch close to the cooker and in your eye line and you'll soon get used to turning it on and off. So much so that you'll be looking for the switch when using another cooker somewhere else ?. In the same way that I look for the whale gulper switch when taking a shower in houses and hotel rooms and forget to put the plug in when running a bath.

Something like https://www.12voltplanet.co.uk/waterproof-onoff-rectangular-marine-rocker-switch-with-red-illumination-12v-24v.html maybe. Able to handle 10A, so plenty for a small inverter.

 

Or even put a buzzer on it

[David Mack]

When we bought a new cooker for Fulbourne some years ago it came fitted with 240V spark ignition, but there was also a separate 12V igniter came with it. An easy swap as I recall.