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Everything posted by Omni

  1. Additionally, be careful when placing a pad within a large ground plane. Suggestion: Trying to solder a component in the middle of a large ground plane can be difficult.
  2. MP, What manufacturer/model number laser printer are you using to transfer your artwork/file to Press n Peel? Techiks has stated Hp is a good choice but the latter source did not mention any particular model number etc... Although, most laser printers use a similar method the fusing can be very subjective. Thank you, Omni
  3. Obviously, you did not take the time to read the instructions concerning the 3055H. Here it is again: http://www.eccolink.com/ProductPages/ShowFile.asp?Part=3055H&Type=II Scroll to page four, the variety of programming methods can perform a similar concept as the knight rider. Remember, decay/timing interval is the key word. example: Let us say the smear time will take 250ms to complete, the latter will leave the filament ON longer than a simple flash before proceeding to the next lamp etc... The above calculated time can also be outlined with the majority of halogen lamp bars using the rate of time as calculated above. Remember, the above time can EASILY be re-calculated and adjusted in the event the example time (250ms) is longer-shorter per bulb or all bulbs actively on with smear present on each bulb until the cycle repeats. Again the key word is "TIME" the halogen does not know it is smearing a flash, the only relative aspect is ON - Decay - OFF; time! I realize the above may be a lot to understand all at once, and it is apparent this thread is beginning to become a back and forth issue. Additionally, your claim concerning the high current pulses that destroy the filament is also subjective, the filament of a halogen is very rugged in comparison to the typical filament; practically all filament lamps draw current, this is not uncommon. The 15-20A as require for the ecco/tomar halogen bar lamp is required because they are for EMERGENCY use, they are more than likely illuminating in a burst that exceed the actual rating of the bulb; extremely bright! The latter is a very good reason for having a Day/Night switch! Furthermore, under normal conditions as would be the case with a typical project the filament life would last the duration of hours intended by the manufacturer. I stress the "FACT" that many Federal, Military, Govt and local authorities have been using flashing halogen lamp assemblies grouped in either a cluster or bar pattern for years. Please, show/link a source where you received your information concerning flashing halogen. Otherwise, you should refrain from providing false accusations that prevent the individuals within this excellent forum from experimenting. Many of the forum individuals are new to electronics and depend on an engineering staff for answers. -Omni
  4. Hi MP, I agree, the Digital voltmeter kit is an excellent project. -Omni
  5. Ugh, Tomar has a variety of "flashing halogen" police & tactical/military (Govt) lighting that uses many variations of "timed/alternating/flashing", not limited to the example i provided. The project you outlined is basic in comparison to the designs available through Tomar. The below is another example how a group of halogen lamps are used in a programmable application, user can select a particular pattern of flashing lamps. http://www.eccolink.com/ProductPages/LightBarsHMPG.cfm 3055H Federal, Military, Govt and local authorities have been using flashing halogen lamp assemblies grouped in either a cluster or bar pattern for years. The point here is "FLASHING" the latter concept is usually programmable in the variety of BAR assemblies. About the only serious drawback when using flashing halogen is Current demand, most programmable flashing halogen bar's require around 20A! :o
  6. Let me try to explain this in an easy to understand manner... ::) A halogen lamp uses a tungsten filament that is encased inside a much smaller quartz envelope. The gas within the envelope is also unique and contains interesting properties. The latter gas combines with a tungsten vapor which when hot will also combine with the tungsten atoms as they start to evaporate and redeposite on the filament. The above is very unique, similar to a recycling process which allows the filament to last longer. Obviously, flashing a filament is not the perfect solution in comparison to a silicon arrangement. However, in the event one chooses to select a brighter, more pronounced illumination the halogen will far exceed the typical filament lamp. example: http://tomar.com/products/selfcontsys/police_light.htm I hope i have made the information above clear enough. :)
  7. Personally, i would use a string of 12V halogen, the level of crisp bright light is far superior than any LED; my opinion. However, the above will require a variety of power transistors to sink each lamp. Halogen is a decent long lasting bulb with excellent illumination: http://www.radioshack.com/product/index.jsp?productId=2062389&cp=&sr=1&origkw=halogen+lamp&kw=halogen+lamp&parentPage=search The above is the same bulb used on the 1986 - 1989 Third brake lamp assembly. Sadly, so many idiots pay $24.00 for this bulb from GM... -Omni
  8. Hi Quincy, What will the amplifier be used for? Audio equipment or Instrument amplification? In the event you plan to build a single channel amplifier for an Instrument; Guitar/Bass etc... Perhaps, you may desire the aura of tube amplification since it far exceeds silicon concerning instrument amplification. Should you be willing to give it a try pick up Kevin 0 Connor's famous book which provides a wealth of detail concerning a variety of legendary tube amplifiers. http://www.londonpower.com/books/tut3.htm or http://www.tubesandmore.com/ Search box type = B-891 Kevin is probably the most knowledgable individual in reference to amplification (valve). Additionally, he will answer any email regarding questions while building one of his designs. -Omni
  9. http://www.safetyenforcement.com/stungunlaws.html -Omni :-\
  10. True, Bias a TIP120 or TIP35 from the output of the 555 (depending on current demand). Battery suggestion: 6V Lantern. In the event the project requires less weight due to mobility experiment with a couple High current C cells (nicad).
  11. "I'm just beginning to get into electronics and stuff, so I may be visiting this site regularly!" What part of the above sentence do you not understand? A functional VOM (analog) is usually a part of every test bench, since the above individual is new to electronics learning to use an analog meter with multi-ranges will only increase his versatile envolvement. Accuracy concerning a meter is determined by the individual reading the movement. Although, the meter he described may have a few issues the latter is a great place to start concerning a first project for troubleshooting. -Omni
  12. Learning how to use an analog meter is essential, understanding the multi-ranges will provide a keen experience concerning other measuring devices. Example: Remember, learning boolean algebra as applied to digital circuits? The calculations as to how they were applied seemed somewhat vague. However, once the above is applied into its useable form concerning (gate fashion) it all made sense! The above measure of understanding allows more advanced expressions to visualize. One can look at an analog meter from a similar perspective. I have an assortment of digital meters but always keep my Simpson 260 at reach. Being able to view a basic RC time constant is a lot more practical when using the analog variety. Viewing first hand the linear swing of a movement is very satisfying. ;) -Omni
  13. http://www.imagesco.com/articles/1490/01.html Read through the above post/link, the information along with detailed drawings may be what you are looking for. -Omni
  14. Hi blueroomelectronics, The type drill press you provided in the pic is not a good choice for PCB drilling. Remember, when looking at a press other than a dremel always firmly grab the chuck (jaw) and shake it to feel if their is ANY horizontal movement. Typically, PCB drilling requires an index from #55 - #60 which are extremely thin bits/rasps. Any horizontal movement concerning the chuck can easily cause a distorted hole. The picture you provided (drill press) is more oriented to chassis hole drilling etc... A dremel is the perfect drill for PCB use since the chuck is directly connected to the motor shaft. Furthermore, purchase the dremel press since it is matched for the dremel drill! Honestly, i like to use a dremel off of the press (hand use) since i can achieve a good feel for required pressure. However, if you plan to use a dremel (hand use) always make sure your drilling is a straight pass through the PCB, avoid any angle etc...
  15. Whoa Chris! The press you built resembles one of those unique inventions Leonardo da Vinci tried to build... Listen, if you are ever a cast-away on a deserted island i am "POSITIVE" you will survive!
  16. The Astro-Med dash10 is a high end multi channel chart recorder used to chart a multitude of variables in graph form. The results while testing will show conclusive if an outside problem has occured. Additionally, how you can criticize Agilent is totally beyond my understanding, the latter manufacturer has some of the most intelligent/professional engineering based throughout the World. I have been employed as a Govt electrical engineer for a long time, during the latter time we cater to Agilent for their superb support. The Agilent method of testing a power supply is essentially the same concept used by a variety of high end resource facilities. I agree with MP, the aspect of going into a deep discussion would be pointless... However, i will provide a hint concerning how to perform temperature stability. Hopefully, it will provide some useful insight. Example: Thermal plate, NI multipoint thermometer using specific locations on the plate (multiple thermocouplers), 2 - Neslab chillers (hot - cold), hot supply tank, cold supply tank along with programming in visual basic or C+ in reference to transistion/cycle time connected via the RS-232 port. indulis, This subject is becoming rather tiring, i would think with a so-called University degree you would have an idea as to how the above is performed? Take the time and keep yourself up to date regarding new concepts, the latter will prove to be very helpful. audioguru, You appear to enjoy continuing a losing argument, your method of testing is very subjective. After reading other threads/posts it is obvious you cannot accept a failure, the latter is the only way you will step beyond your superficial ego; learning is a virtue! MP, "(In other words) You have made your opinion. Let it go." DITTO!
  17. Placing a sheet of PnP (blue) into a copying machine and using your artwork on the top plate will work but the end result will be a 2nd generation output. Since the process above must be performed in 2 steps, the internal copier generates an image then the image is fused to the PnP. Printing your artwork from file to PnP using your computer is a much better procedure. I have used both methods and believe the PnP bond to copper is more pronounced using a laser printer. The Hp B&W line have been verified by Techniks. Remember, PnP does require some experimenting and the better equipment you have will produce an overall more pleasing result. Example: a small PCB where the typical household iron will completely cover the copper clad board will allow a good transfer since you are holding/pressing the iron firmly overtop of the board. However, if your board extends beyond the bottom of the iron (heat surface) you are forced to move the iron back and forth over the board, the result can easily cause the transfer film to flex causing a track to smear. The above can be corrected by using a larger surface iron that will cover the board or a heat press. The less horizontal movement required will produce a more defined PCB.
  18. Designing a PCB is not as easy as one would believe. Example: audio amplifier circuit; Tube & Silicon. Unfortunately, most PCB software defaults to linking the ground plane to all components with a connection to the ground net. One must manually exclude each of these with "forbidden" areas in the ground plane polygon, or designate the circuit ground differently from the ground plane. Remember, your study on galactic grounding principles, small current grounds (preamplifier) and large current grounds (poweramp) should never be tied together or in close proximity. Additionally, power nodes should each have a seperate ground and chassis wiring must be routed correctly. In the event you elect to try a tube amplifier design consider using a DC standoff voltage vs the typical layout. The problems that arise from failure to understand the above rules are endless; oscillation, squeal, feedback along with many other variables.
  19. Fear does not resolve into any formal test, maintaining a controlled method is an engineering approach/method that deserve's merit both from a logical standpoint along with a more calculated technique! Furthermore, i stress a prior post notation: The above is an abridged Agilent power supply test method that is used within the engineering community. Additionally, i am not sure as to the level of control your concept will provide. Please, understand i did not make-up the procedure. The above outline is a proven method used throughout the industry both in Government and Commercial sectors.
  20. Load Transient Recovery time Load Effect Current Limit Characterization PARD Efficiency & Power Factor Start-up response Turn-off response Temperature variation The above is an abridged Agilent power supply test method that is used within the engineering community. Additionally, i am not sure as to the level of control your concept will provide. Truthfully, it would be best to use an electronic DC Load that is much more controlled. I mean no disrespect concerning your method but would rather use a more defined approach. Maintaining a controlled temperature variation while testing is difficult to achieve on a normal test bench using large power resistors. Furthermore, charting the test using a recorder has many advantages, one could easily view an outside parameter that placed the UUT in a non-linear (abnormal) condition. The latter failure may not have been the UUT but rather the uncontrolled method of test. However, what i may consider notable you may believe otherwise.
  21. Any of the three will provide adequate protection concerning soldering. However, if in doubt you can contact 3M EHS Department. http://www.3m.com/ Select the particular location and use the contact sheet (email).
  22. Are you familiar with the curriculum requirement concerning Electrical Engineering? In order to take an Advanced class study at Penn it is usually administered on a Graduate level. A variety of courses are necessary before the latter course is even available. My home laboratory could never duplicate the available test instruments at any University where most of the more elaborate stress testing was performed. A basic Astro-Med Dash10 that most Universities have in multitudes is outside of my home lab affordability. One has to take advantage of other resources when available, i believe you get the idea...
  23. Hi Pajarico, A fume extractor will not cause any cold solder joint problems, the latter is extracting the air away from the solder joint. True, it is not advisable to blow on a solder joint while it is forming, the latter is also true in reference to cleaning the joint with alcohol. Always wait until the joint is solid, if you clean the joint with an alcohol brush and hear a fizz you applied the alcohol before the joint formed (solid); simply re-flow joint etc...
  24. The below link appears to have many F/X circuits/schematics etc... Building a multiple effect unit is simple combining a group into a controller. Regardless, as to viewing the effect as pure digital is subjective, generally somewhere in the path a D/A - A/D is occuring. Eventide along with Lexicon may claim pure digital but practically any audio engineer will cater to some analog mix within the path; pure digital can sound very synthesized. http://www.tonepad.com/projects.asp?projectType=fx
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