EggTimer Quasar not working....

[Charles_McG]

I had a hot regulator on a TRS that I never did figure out.

 

[Voyager1]

You got it, it was the tiny FET, the lead was sitting just a smidge (like less than a human hair) above the solder. It could not be seen from above, just close inspection from the side.

Just out of curiosity, what magnifier and illumination are you using for soldering these boards?

 

[darrenf]

Just out of curiosity, what magnifier and illumination are you using for soldering these boards?

While soldering I am using this...

https://www.amazon.com/dp/B08XJLF9NX?ref=ppx_yo2ov_dt_b_product_details&th=1
It doesn't list the magnification but I'd guess it's about 5x. The loupe I use for inspection after soldering is a 10x.

 

[AnalogtoDigital]

Just out of curiosity, what magnifier and illumination are you using for soldering these boards?

I cannot speak for Darren, but I use the headlamp magnifier from Harbor Freight along with the Magnifying lamp to flood the area with light.

 

[darrenf]

I cannot speak for Darren, but I use the headlamp magnifier from Harbor Freight along with the Magnifying lamp to flood the area with light.

Don't know if I'll use it while working on these boards, but that headlamp magnifier looks fantastic. I'm going to order one!

 

[AnalogtoDigital]

Don't know if I'll use it while working on these boards, but that headlamp magnifier looks fantastic. I'm going to order one!

The headlamp was a game changer for me, the old one I was using had a frame around it that limited vision. The table lamp I use more as a flood light, Dad will actually use it to repair work. ( Old dog that has used one forever)

-Edit One more thing, the headband is kind of slick until you get an hour or two of wearing it.

 

[Voyager1]

You got it, it was the tiny FET, the lead was sitting just a smidge (like less than a human hair) above the solder. It could not be seen from above, just close inspection from the side.

Something I noticed on some of your images was the inability of the solder to flow over some of the leads and pads evenly, forming a nice meniscus. In most of these cases I suspect that the reason was due to oxidation on the pads. When this happens, the solder will not wet the pad and tends to ball up around the lead. This can happen more often when the iron temperature is too low, but can still happen at higher temperatures.

I was motivated today to build a Quasar kit I’d purchased months ago, mainly as a result of this current discussion. Prior to soldering, I inspected the board pads for oxidation and found several pads oxidised and grey, not with clean and shiny tinning. Generally when I find pads like this on PCBs I use a scouring pad or coarse eraser on the pads to remove the oxidation and leave a clean shinier pad. Additionally, I will use IPA to remove any oily or greasy residues.

 

[darrenf]

Something I noticed on some of your images was the inability of the solder to flow over some of the leads and pads evenly, forming a nice meniscus. In most of these cases I suspect that the reason was due to oxidation on the pads. When this happens, the solder will not wet the pad and tends to ball up around the lead. This can happen more often when the iron temperature is too low, but can still happen at higher temperatures.

I was motivated today to build a Quasar kit I’d purchased months ago, mainly as a result of this current discussion. Prior to soldering, I inspected the board pads for oxidation and found several pads oxidised and grey, not with clean and shiny tinning. Generally when I find pads like this on PCBs I use a scouring pad or coarse eraser on the pads to remove the oxidation and leave a clean shinier pad. Additionally, I will use IPA to remove any oily or greasy residues.

That sounds like a good tip. I will definitely inspect boards before I start on my future projects.

 

[waltr]

Do you have an inline meter you suggest to check the current draw? Does the RC world have something we could use?

Also, thanks again for all your help with this.

An easy way is to measure the Voltage drop across a low value resistor with a DVM. Then Ohm's Law to calculate current, I = E/R.
A 1 Ohm resistor makes the calc trival and is about the right resistance for 100-200mA. DVM reads 100 - 200mV
If the battery Voltage is high enough a 10 Ohm resistor will also work. DVM reading will be 10 time current (1-2V).

 

[darrenf]

@cerving ,
Well, got around to vacuum testing the 2nd Quasar today, the one that seemed to be working fine. Unfortunately it isn't. I attached the flight info from the unit. Drogue and main fired simultaneously well after vacuum had been broken (about 2 seconds) and the device was back at ground air pressure.

Here is the text from the flight summary...

DWFQuasar1 1.02d

Flight Summary

Flight No.: 4
Flight Status: Landed

Apogee:.........44639
Time to Apogee.....17.65

Max Velocity.....2793 (Est.)
Time to MaxVeloc.....1.05

Avg Accel(G).....82.61 (Est.)

LDA Alt.........22524
Time to LDA.....0.00

Nose-Over Alt...59656
Time to Nose-Over.....24.50

Drogue Alt......59656
Time to Drogue.....24.50

Main Alt........59656
Time to Main.....24.50

Flight Time.....31.50

ASL Alt.........-1
Temp. F.........-0.1

Settings
LDA Alt.........200
Launch Samp./sec...20
Descent Samp./sec...2
Drogue Delay...0.0 sec
Drogue On-Time...2
Main Alt...300
MAIN On-Time...2
AUX: OFF


FailSafe Settings
FailSafe...OFF

 

[Tractionengines]

Vacuum chamber testing is NOT a good way to do close evaluation of altimiter function. The pressure drop on simulated accent, and the pressure build up on the simulated descent are the wrong shape. This causes the "filtering" that is built into altimiters to do strange and unpredictable things.

At best a vacuum chamber test lets you say. Yep the altitude went up as pressure went down, and the channels fire electrically confirming the output(s) work... that's it.

ie. the filtering to smooth wind induced fluctuations does some averaging and delays. Plus Mach lockout prevents the charges firing if the logic predicts the speed is still above Mach. If Mach is exceeded during the down phase, who know's what happens.

My guess is the logic locked out the channels, then they both fired after the "lockout" passed.

 

[Voyager1]

Your ASL Alt and temperature figures in the flight summary seem odd. What do they report on the status page when you just connect to the Quasar via wifi normally. Also, the apogee, launch detect and nose-over altitudes are weird. I’m wondering whether your barometer is being read correctly.

How did you vacuum test the board? In a jar with a pump, or a straw test? Typically, when you perform these vacuum tests, you won’t get the correct flight pressure profile, so the drogue and main outputs will generally fire simultaneously.

I would repeat it, but with a more gentle vacuum.

 

[darrenf]

Vacuum chamber testing is NOT a good way to do close evaluation of altimiter function. The pressure drop on simulated accent, and the pressure build up on the simulated descent are the wrong shape. This causes the "filtering" that is built into altimiters to do strange and unpredictable things.

At best a vacuum chamber test lets you say. Yep the altitude went up as pressure went down, and the channels fire electrically confirming the output(s) work... that's it.

ie. the filtering to smooth wind induced fluctuations does some averaging and delays. Plus Mach lockout prevents the charges firing if the logic predicts the speed is still above Mach. If Mach is exceeded during the down phase, who know's what happens.

My guess is the logic locked out the channels, then they both fired after the "lockout" passed.

I'll try it a different way then. But my vacuum chamber resulted in great simulations and accurate data for my Quark, Quantum and Ion units.

 

[waltr]

I have been able to obtain a reasonably good air pressure flight profile with my simple vacumn chamber.
It has a small orface that prevents quick pressure changes plus not releasing the vacumn source quickly. Have used this on all my eggtimer builds and when download and plot altimeter data see a quick up and much slower down that looks like a real flight.
With Xmass tree bulbs on the outputs each will turn on in sequence and the appropriate altitudes.

Just can't test Quantum with Accerelometer conditions enabled.

Darren, Did the downloaded Altitude profile look like a typical flight?

 

[darrenf]

I have been able to obtain a reasonably good air pressure flight profile with my simple vacumn chamber.
It has a small orface that prevents quick pressure changes plus not releasing the vacumn source quickly. Have used this on all my eggtimer builds and when download and plot altimeter data see a quick up and much slower down that looks like a real flight.
With Xmass tree bulbs on the outputs each will turn on in sequence and the appropriate altitudes.

Just can't test Quantum with Accerelometer conditions enabled.

Darren, Did the downloaded Altitude profile look like a typical flight?

They did not, but with every other EggTimer kit I've tested in there the results did look like a normal flight outside of the crazy acceleration numbers. I did post my results if you wanted to check them out.


Also, what accelerometer conditions are you referring to? To the best of my knowledge neither the Quantum or the Quasar have an accelerometer on board.

 

[cerving]

I have said this many times before...

Vacuum tests are NOT a good parametric test, they are only a good FUNCTIONAL test. The reason that your velocity figure is so high is that the vacuum is being pulled very quickly, compared to an actual flight. Similarly, the vacuum gets dropped very quickly when you turn it off. By the time that your vacuum has been dropped for one second to detect nose-over, you've already hit your Main chute's altitude... which is why they appear to fire simultaneeously.

Download the flight detail data and graph it, you'll see what I mean. It will look just like a high-speed ballistic flight. There is nothing wrong with your hardware.

The only way to get a realistic altimeter vacuum test is to use a vacuum pump and have some kind of accumulator tank so that the vacuum doesn't get pulled or dropped too quickly. Even then, you have to be able to drop the vacuum much slower than you pull it, or it's going to look like a ballistic flight every time.

 

[waltr]

Sorry, it is the Proton with the accelerometer. I use this on a 2-stage.

Cris, If you control the pressure drop and then pressure increase rates you can get very close to a simulated flight.
3-6 seconds to minimum pressure then 20-40 seconds to back to ambient pressure.

 

[cerving]

Sorry, it is the Proton with the accelerometer. I use this on a 2-stage.

Cris, If you control the pressure drop and then pressure increase rates you can get very close to a simulated flight.
3-6 seconds to minimum pressure then 20-40 seconds to back to ambient pressure.

Correct, however very few people have the capacity to properly control the pressure rates with a pump, and it's pretty much impossible with a vacuum cleaner. You can kinda sorta do it with one of those big syringes, if you get enough practice, but you have to put some silicone lube on the plunger to keep it from "chattering" and giving you some very noisy readings.

 

[waltr]

I control the vacuum with a small orface and a vacuum clearer. It just takes a little practice.

 

[StreuB1]

@cerving , Just curious, how warm should the 3.3v Voltage Regulator get. I'm reading about 130 degrees F when the Quasar is sitting at idle.

I had a hot regulator on a TRS that I never did figure out.

I also have a smokin hot regulator on my Quasar as well as one of my mini GPS's. The GPS's regulator got so hot at Airfest last year that it melted the plastic baggie I had it in to seal it from ejection gases in the nomex blanket. I ended up removing it and bench testing it and it gets wildly hot so unfortunately it sits unused in my electronics box.

Never did figure out why either are like that as I have a lot of experience soldering, have a proper solder station with all the right tips and an inspection glass. All is good on both of those boards but alas, they get really hot. The Quasar works fine, the mini GPS, does nothing.

 

[schworer]

I also have a smokin hot regulator on my Quasar as well as one of my mini GPS's. The GPS's regulator got so hot at Airfest last year that it melted the plastic baggie I had it in to seal it from ejection gases in the nomex blanket. I ended up removing it and bench testing it and it gets wildly hot so unfortunately it sits unused in my electronics box.

Never did figure out why either are like that as I have a lot of experience soldering, have a proper solder station with all the right tips and an inspection glass. All is good on both of those boards but alas, they get really hot. The Quasar works fine, the mini GPS, does nothing.

A linear regulator basically converts the difference between input voltage and output voltage into heat. What is your battery voltage?

 

[Steve Shannon]

A linear regulator basically converts the difference between input voltage and output voltage into heat. What is your battery voltage?

Also, what the current. That’s really what results in heat.