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Far Infrared Source Needed
I need a 10 micron infrared source for some pyroelectric detector testing. Prefer a fairly low-cost approach. I used an incandescent lamp with the glass bulb removed. The driving circuit was a constant current source. This worked - for a week - until the tungsten filament fused.- turbo22
- Thread
- Replies: 1
- Forum: Electrical Engineering general discussion
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Using Current Transformer to Step-Up Current
I need to generate about 100 mA from a 60 Hz source by driving a GFCI grounded-neutral current transformer (in reverse). Neglecting transformer losses, if I use a 250 turn primary and drive it with 400 uA, theoretically, I should be able to extract 100 mA from a single turn secondary (a single...- turbo22
- Thread
- Replies: 2
- Forum: Circuit design
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Sourcing Transformerless AC/DC Converter IC
Contact Rohm Electronics. They make a series of AC/DC power modules that are very easy to implement. Example: BP5034D12 converts 120vac to 12vdc. They probably have 220 vac modules also. Be Careful - you don't have line isolation for protection. Your circuit ground will be line neutral and...- turbo22
- Post #3
- Forum: Circuit design
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ac current source
One possibility is to use a CT (current transformer) in reverse. Assuming a 1000:1 turns ratio, you could apply 20 mA to the input side and extract 20 Amps from the output. (You might watch your impedance transformation for problems). Building a 20 mA current source would involve a simple...- turbo22
- Post #3
- Forum: Circuit design
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RS232 Isolated Interface Circuit Assistance
I have designed an isolated RS232 interface for a PIC16F877 circuit. Isolation is necessary since my circuit is powered from a direct mains regulator (no power transformer). I'm using a MAX232 converter and a couple of 4N35 optoisolators for the TX/RX paths. At 19200 baud, I'm starting to get...- turbo22
- Thread
- Replies: 6
- Forum: Circuit design
