Voltage Regulator to Power Up Glow Plug from Receiver Battery.

[lazy-b]

Voltage Regulator to Power Up Glow Plug from Receiver Battery.

Guys, I like to make a very High efficient Voltage Regulator to Drop a 5.0 Volts from Receiver Battery to 1.5 Volts 4 Amps to power up a Glow Igniter.

I've been using one for my Helicopter, its made by Futaba GH-1, It directly plug to any receiver open channel.

I plan to install all my Helicopter and Plane with On-Board Igniter.

Have alreay tried a Linear Regulator such as LX8383....produce to much heat and I have to Connect it directly to Battery, due to too much current.

Have also tried a simple 555 as PWM, this need also connected to Battery , due to too much Peak Current.

I've seen somebody have done it using a Single Chip Switching regulator ICs and an Inductor and Capacitor.......its very few component......or any suggestion.

Ellion

[lazy-b]

Guys, Found this simple Glow Plug Driver from other Jet Forum (designed by Jet-Mad Richard)....he use this circuit for his JetJoe Engine.....The circuit is designed for 7.2 Vots, maybe I can modify it to works on 4.8 Just matter of changing the winding.

Its not even using any ICs, just a plain discrete component.....I guess, its very easy to get that Donut shape ferrite core.....Just get it from an old defective computer power supply.

Ellion

[Acetronics]

Hi, Ellion

Here you will find the All-in-one package ...

http://lichtenberger.s.free.fr/GlowSL.htm

Alain

[lazy-b]

Hello Alain,

Thanks for the Links.....Sorry, I can not understand it. but from the look of its circuit, I guess, its a Glow Plug Igniter Switch. with this circuit. you need an extra 1.2 Volts Nicad to power the Glow Plug........But I guess, its a very interesting circuit with programmable output.

I just wonder if we could use PIC Controller a Voltage Regulator, and at the same time we could use its Build-in A/D converter, to measure its Current Flow and can use a 10 pcs LED at Current indicator.

Thanks anyway.

Ellion

[Acetronics]

Ellion,

I certainly would not had given this link if the glow plug was not to be powered from 4 cells ...
Rx cells i.e.

just "babelfish" it !!! to read ir in English ...

The design works fine, I've tested it ... just a bit "jerky" with Tx switched OFF ... but it's not supposed to be so ...

I personnally would not recommend that usage ...

but you want to do like that ... LOL !

Alain

[lazy-b]

Alain,

after Translation......Now, I understand it....

The Circuits works just like a Variable Duty Cycle Timer 555 (PWM)......You can not connect this circuit thru a receiver due to Huges Peak Current.

Thanks Again.

Ellion

[Acetronics]

Hi Ellion

Either "buck" switching regulator with an Enable pin will do the job ... see LM2576 or here :

http://www.aca-vogel.de/DCDC-Converter/8AfromLM2575_en.html

jst need to convert the channel output to ON/OFF ...

for 4v8 ... see LM1771 or equiv i.e.

Alain

[jeffs555]

Haven't done the math, but would expect that a simple LC filter between the battery and the PWM circuit would average out the peaks and let you use the simple variable duty cycle PWM. Higher PWM frequencies would allow smaller L and C in the filter.

[lazy-b]

Alain,

look like this LM1771 is the perfect chip for my application, its design for 2.8 to 5.5 Volts Input, with an efficiency for more than 90%.....asuming the glow plug consume 3 Amps at 1.5 Volts thats 4.5 Watts at 90% efficiency the current drawing from the receiver should be about (4.5 Watts/0.9) / 5 Volts = 1 Amps

Luckily its available at www.farnell.com cost about USD 3 each.............THANKS Again.

Jeffs555, Yes......your Right......It will average out, to drop a 4.8 Volts to 1.2 Volts you need a Duty cycle of about 25% , so 4.8 Volts X 25% = 1.2 Volts , its the same with peak current of 16 Amps Peak Current X 25% = 4 Amps Average...... this is just an estimate......I guess, most of the Glow Plug Power Panel uses this kinds of Circuits, Just need a single 555 timer and Power Mosfet.......Inductor and Capacitor is not need, since the load is not that critical.

Have tried using this methods, I connect the igniter circuit directly to the Battery.....it work perfectly.......I guess, there is a cheaper version, just use a simple resistor to drop a 4.8 Volts to 1.2 Volts Maybe a 1 Ohms 5 Watts is enought.

been using a Simple Linear regulator to drop 4.8 Volts to 1.2 Volts, assuming a current of 3 amps...this means I have to dissipate the Heat of (4.8-1.2) X 3 = 10.8 watts of Heat, if I add a dropping resistor of 0.5 Ohms, this will drop the regulator Input to 3.3 Volts , the resistor will be dissipating 4.5 Watts and the Regulator will be dissipating (3.3-1.2) x 3 = 6.3 watts

Might need a simple heat sinking maybe a 1 inch x 2 inch x 2 mm Aluminum sheet is enough, for more Heat Absorbing, I can just dip the whole circuit into EPOXY BLOCK so that some heat will be absorb by the epoxy.

An On-Board Igniter is applicable if you use a High Capacity Battery such as Sub-C 2400 MAH Battery.

This On-board igniter can be use as a LOADING to the Battery, to test the Strength of the Nicad Battery.