In interest of full disclosure, I'm not an EE and only have a small amount of practical experience with electronics. I get the concept and can read a schematic pretty well, and I've put together a number of projects from schematics successfully, but when it comes to building a circuit from scratch, I know my limitations and ask for help.
The project is a 555-type circuit that triggers both a piezo and a bank of LEDs on a variable time delay. I'm building a reusable flashbang device for military/law enforcement training exercises, so it needs to be both loud and bright, but within safety requirements for repeated exposure. The LEDs I have in mind are something like these:
RL5-W18030 Super White LED specs
They need to be as bright as possible. The piezo needs to be capable of producing ~90db at 1 meter. Power source should be common AAA, AA, or 9v type (depending on power requirements). The whole circuit will be mounted in a cylindrical body with an adjustable resistor (to adjust delay time) and a push-to-break switch (to start the timer) at one end, and the piezo at the other end to allow it to sound unimpeded by the housing. The housing will be ~1.5" in diameter, with holes drilled in a configuration of 5 rows x 10 LEDs/row and the LEDs mounted flush with the surface of the housing (so that they are not damaged when the unit is thrown/rolled on concrete). The housing will be rubberized to reduce shock, and the circuit may need to be mounted in such a way as to resist shock. I'll worry about the mechanical details of the switch release, appropriate mounting, etc, it's the electronics I need help with. I don't want to breadboard it, I want to wire and bundle this circuit in as small an inline package as possible, to be mounted to the inside of the housing.
I've found a couple of timer circuit diagrams online, like this one (Adjustable 1-10 Minute Timer Project), but I want a shorter timer (1-10 seconds, instead of minutes, and with only a half-second or shorter pulse time), lose the "off" LED, and use a bank of "on" LEDs, make sure the power requirements are there for the number and rating of the LEDs and for the piezo. What I don't know, due to lack of experience, is the best way to approach this. Most of the common timer circuits are meant to behave very differently, and I don't know if starting from one of those and tweaking to my requirements is a good way to go, or if there is an entirely different approach that would be better.
I'm willing to pay (a reasonable price) for a schematic and parts numbers if someone can put together something that meets my requirements. Email me to discuss it before putting the work in, though.
ryanm
ryanm@horsefish.net
The project is a 555-type circuit that triggers both a piezo and a bank of LEDs on a variable time delay. I'm building a reusable flashbang device for military/law enforcement training exercises, so it needs to be both loud and bright, but within safety requirements for repeated exposure. The LEDs I have in mind are something like these:
RL5-W18030 Super White LED specs
They need to be as bright as possible. The piezo needs to be capable of producing ~90db at 1 meter. Power source should be common AAA, AA, or 9v type (depending on power requirements). The whole circuit will be mounted in a cylindrical body with an adjustable resistor (to adjust delay time) and a push-to-break switch (to start the timer) at one end, and the piezo at the other end to allow it to sound unimpeded by the housing. The housing will be ~1.5" in diameter, with holes drilled in a configuration of 5 rows x 10 LEDs/row and the LEDs mounted flush with the surface of the housing (so that they are not damaged when the unit is thrown/rolled on concrete). The housing will be rubberized to reduce shock, and the circuit may need to be mounted in such a way as to resist shock. I'll worry about the mechanical details of the switch release, appropriate mounting, etc, it's the electronics I need help with. I don't want to breadboard it, I want to wire and bundle this circuit in as small an inline package as possible, to be mounted to the inside of the housing.
I've found a couple of timer circuit diagrams online, like this one (Adjustable 1-10 Minute Timer Project), but I want a shorter timer (1-10 seconds, instead of minutes, and with only a half-second or shorter pulse time), lose the "off" LED, and use a bank of "on" LEDs, make sure the power requirements are there for the number and rating of the LEDs and for the piezo. What I don't know, due to lack of experience, is the best way to approach this. Most of the common timer circuits are meant to behave very differently, and I don't know if starting from one of those and tweaking to my requirements is a good way to go, or if there is an entirely different approach that would be better.
I'm willing to pay (a reasonable price) for a schematic and parts numbers if someone can put together something that meets my requirements. Email me to discuss it before putting the work in, though.
ryanm
ryanm@horsefish.net