Help! max current draw for ar620, per channel

kinch

Member
I need some advise on running LED's light on the aux channel of a receiver. The LED strip draws 300m (actually 2 @ 150mA). I have a Apex switch, just not sure at what point you could burn up the receiver. Is it safe?
 

Merv

Site Moderator
Staff member
I need some advise on running LED's light on the aux channel of a receiver. The LED strip draws 300m (actually 2 @ 150mA). I have a Apex switch, just not sure at what point you could burn up the receiver. Is it safe?
A 300 mA draw will have no adverse effects on the Rx. A 9g servo can draw 750mA.
 

Bricks

Master member
What does your ESC put out for amps would be my big question and how many servos as low voltage will definitely give you a brown out.
 

kinch

Member
What does your ESC put out for amps would be my big question and how many servos as low voltage will definitely give you a brown out.
35Amp ESC, 5 servos, 3S45C...(Simple Cub, 4 channel, with a bomb bay for parachute drop)
 

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Merv

Site Moderator
Staff member
I agree with @Bricks, if your BEC is 3A or less you would be running the risk of a brown out, with the lights on. You may be able to get away with 3A, if your just doing lazy circles in the sky. With a 5A BEC you'll be able to hammer the sticks all you want.
 

kinch

Member
It's a flight test 35Amp ESC, with 5V/3Amp BEC. Motor is Suppo A2208/17T 1100kv. I love Flight Test and have both B and C power packs, but I love this Suppo motor. It is so quite in flight with the Simple Cub, that you can't hear it at times, and flys for 18 minutes, on a 1300mA, 35C Lipo. I fly around a park by my house, just easy flying. I have Flaperons, and added another servo so I can drop a parachute on the bottom of the fuselage.

Another question...on the AR620, what is the BATT (pin 1) used for? Can you plug in the LEDs there?

Also, when you use a servo, isn't it just a pulse, not a constant current draw?
 

Merv

Site Moderator
Staff member
Another question...on the AR620, what is the BATT (pin 1) used for?
The Batt pin is used for glow engines, it supplies voltage from a 5V flight pack to the Rx and leaves all the channels open for use. A servo would be pugged into the throttle channel to operate the engine's throttle. In the Rx, all of the positive pin are connected and all of the negative pins are connected. Voltage can be supplied by any channel. The BEC, battery elimination circuit, eliminates the need for the 5V flight pack.

Also, when you use a servo, isn't it just a pulse, not a constant current draw?
The amps a servo draws depends on the pressure on the servo arm. If the servo arm is at any given position and there is a force trying to move the arm. The servo will draw amps trying to hold that position. Little pressure equals low amp draw, high pressure equals high amp draw. When you stall a 9g servo, the maximin amp draw, it will draw about 3/4 A or 750 mA. Four servos, all drawing the maximum would be a 3 amp load.

If you are flying lazy circles in the sky you will likely be fine, but if you start hammering the sticks, you run a risk of a brown out while running the lights.

Myself, I run 12V LED's and power them from my 3S flight pack. I tap the balance lead for lights.
 
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kinch

Member
Great information...thanks for all the help. It is much appreciated. It is amazing how little information you find if you Google it.

I have a 300mA 1S LiPo I use for an OMP S720. I might just use it and leave the main battery alone. The LED's I have are the cheap "kite" led's from Bangood. They are very bright, but you may wait a few months to get them.

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