PREDATOR - valveless PDE build blog
Moderator: Mike Everman
-
- Posts: 2158
- Joined: Sat Oct 04, 2003 2:35 pm
- Antipspambot question: 125
- Location: Normandy, France, Wales, Europe
- Contact:
Re: PREDATOR - valveless PDE build blog
Very impressive work, well done
Viv
Viv
"Sometimes the lies you tell are less frightening than the loneliness you might feel if you stopped telling them" Brock Clarke
Viv's blog
Monsieur le commentaire
Viv's blog
Monsieur le commentaire
Re: PREDATOR - valveless PDE build blog
thanks, Viv !
Next time I will add some effects to visualize the run parameters. First show effect will visualize the exhaust impulse (damage of a sheet of paper, push-away a paper bin....) . For measurements I will construct a impulse-pendulum to indicate the impulse ( impulse conservation law : m1 v1 = m2 v2) to confirm 1800 m/s exhaust velocity (or whatever it indicates).
Next step is an improved injection and ignition control by Atmega169. Programming is done already, but my #@!?*$&§ Power-Mosfets do need 15V gate voltage, and the Atmega only provides 3,3V. ...Looking for a 15V line buffer (line driver).
zono
Next time I will add some effects to visualize the run parameters. First show effect will visualize the exhaust impulse (damage of a sheet of paper, push-away a paper bin....) . For measurements I will construct a impulse-pendulum to indicate the impulse ( impulse conservation law : m1 v1 = m2 v2) to confirm 1800 m/s exhaust velocity (or whatever it indicates).
Next step is an improved injection and ignition control by Atmega169. Programming is done already, but my #@!?*$&§ Power-Mosfets do need 15V gate voltage, and the Atmega only provides 3,3V. ...Looking for a 15V line buffer (line driver).
zono
___________________________
zono - the thruster buster
--------------------------------------
zono - the thruster buster
--------------------------------------
-
- Posts: 2158
- Joined: Sat Oct 04, 2003 2:35 pm
- Antipspambot question: 125
- Location: Normandy, France, Wales, Europe
- Contact:
Re: PREDATOR - valveless PDE build blog
Hi Zono.
Ok That's all good, for the Mosfets you can try a standard opto-isolator, that will keep your logic devices safe on one side and you can simply power the other side with what ever gate voltage you want.
Pendulum thrust stands are a good choice but watch how you read it and calculate your results, it can be tricky to get a truthful reading as others have demonstrated in the past.
As I said good work, I enjoyed following your test
Viv
Ok That's all good, for the Mosfets you can try a standard opto-isolator, that will keep your logic devices safe on one side and you can simply power the other side with what ever gate voltage you want.
Pendulum thrust stands are a good choice but watch how you read it and calculate your results, it can be tricky to get a truthful reading as others have demonstrated in the past.
As I said good work, I enjoyed following your test
Viv
"Sometimes the lies you tell are less frightening than the loneliness you might feel if you stopped telling them" Brock Clarke
Viv's blog
Monsieur le commentaire
Viv's blog
Monsieur le commentaire
Re: PREDATOR - valveless PDE build blog
Guess I have to eat my hat realy nice work!
With the right software and hardware in place, what kind of detonation frequency do you hope to achieve?
With the right software and hardware in place, what kind of detonation frequency do you hope to achieve?
Quantify the world.
Re: PREDATOR - valveless PDE build blog
@metiz:
I think 1...2 Hz. Filling is the bottleneck.
@Viv:
thanks, opto-coupling is expensive, but you are right! Best for safety.
zono
I think 1...2 Hz. Filling is the bottleneck.
@Viv:
thanks, opto-coupling is expensive, but you are right! Best for safety.
zono
___________________________
zono - the thruster buster
--------------------------------------
zono - the thruster buster
--------------------------------------
Re: PREDATOR - valveless PDE build blog
Good work!
Nice to see one put together.
Nice to see one put together.
-
- Posts: 2158
- Joined: Sat Oct 04, 2003 2:35 pm
- Antipspambot question: 125
- Location: Normandy, France, Wales, Europe
- Contact:
Re: PREDATOR - valveless PDE build blog
Hi Zonozono wrote:@metiz:
I think 1...2 Hz. Filling is the bottleneck.
@Viv:
thanks, opto-coupling is expensive, but you are right! Best for safety.
zono
Sorry expensive? are talking about the same thing, should be cheap as chips.
http://en.wikipedia.org/wiki/Opto-isolator
http://www.electronicrepairguide.com/optocoupler.html
Viv
"Sometimes the lies you tell are less frightening than the loneliness you might feel if you stopped telling them" Brock Clarke
Viv's blog
Monsieur le commentaire
Viv's blog
Monsieur le commentaire
Re: PREDATOR - valveless PDE build blog
hmmm right Viv, I found some opto for less than 1$ .....lets try transistor-optos and triac-optos
zono
zono
___________________________
zono - the thruster buster
--------------------------------------
zono - the thruster buster
--------------------------------------
-
- Posts: 2158
- Joined: Sat Oct 04, 2003 2:35 pm
- Antipspambot question: 125
- Location: Normandy, France, Wales, Europe
- Contact:
Re: PREDATOR - valveless PDE build blog
Hi Zonozono wrote:hmmm right Viv, I found some opto for less than 1$ .....lets try transistor-optos and triac-optos
zono
Keep it simple and go for the transistor ones as it will be easier for you to interface than the triac versions (better for high power operation in PSU)
Viv
"Sometimes the lies you tell are less frightening than the loneliness you might feel if you stopped telling them" Brock Clarke
Viv's blog
Monsieur le commentaire
Viv's blog
Monsieur le commentaire
Re: PREDATOR - valveless PDE build blog
See some details of the test rig:
spark plug, gas injector and solenoid valve
zono
spark plug, gas injector and solenoid valve
zono
___________________________
zono - the thruster buster
--------------------------------------
zono - the thruster buster
--------------------------------------
new run in2012 PREDATOR - valveless PDE build blog
Hi friends,
new runs of Predator were done on DOT (Days of speed and Thunder, big pulsejet meeting in Rothenburg, Germany at 17.-19. May 2012, http://www.pulsotriebwerk.de).
As announced before, I tested MCU controlled gas injection and ignition - with great success!
Now I am posting the first images. More come in the next days...
PS: the supports were rammed into the soil due to the detonation impulses
new runs of Predator were done on DOT (Days of speed and Thunder, big pulsejet meeting in Rothenburg, Germany at 17.-19. May 2012, http://www.pulsotriebwerk.de).
As announced before, I tested MCU controlled gas injection and ignition - with great success!
Now I am posting the first images. More come in the next days...
PS: the supports were rammed into the soil due to the detonation impulses
___________________________
zono - the thruster buster
--------------------------------------
zono - the thruster buster
--------------------------------------
Re: PREDATOR - valveless PDE build blog
and here are the vids:
http://www.youtube.com/watch?v=Nn9I1RXT0TM&feature=plcp
http://www.youtube.com/watch?v=TYLmpxKcnDM&feature=plcp
Detonation shockwaves had awsome intensity. They destroyed parts of my test rig (momentum gauge)
http://www.youtube.com/watch?v=Nn9I1RXT0TM&feature=plcp
http://www.youtube.com/watch?v=TYLmpxKcnDM&feature=plcp
Detonation shockwaves had awsome intensity. They destroyed parts of my test rig (momentum gauge)
___________________________
zono - the thruster buster
--------------------------------------
zono - the thruster buster
--------------------------------------
Re: PREDATOR - valveless PDE build blog
hmmmm
nobody left in the PDE forum? Nobody interested any more? Not even defense industry
have a look above. New runs done in May 2012.
nobody left in the PDE forum? Nobody interested any more? Not even defense industry
have a look above. New runs done in May 2012.
___________________________
zono - the thruster buster
--------------------------------------
zono - the thruster buster
--------------------------------------
Re: PREDATOR - valveless PDE build blog
Will your engines ever be able to run continiously?
Quantify the world.
-
- Posts: 5007
- Joined: Fri Oct 31, 2003 7:25 am
- Antipspambot question: 0
- Location: santa barbara, CA
- Contact:
Re: PREDATOR - valveless PDE build blog
Oh, definitely still interested!
Mike Often wrong, never unsure.
__________________________
__________________________