# Tag Info

1

The TL07x op amps are not rated for rail-to-rail operation. In connecting pin 4 to ground, you are forcing the inputs much closer to V- than they can support. The data sheet specifies limits on the common-mode voltage input (which means the input voltage in this case) as 4 volts above V- to 4 volts below V+, which means that it won't work as you've connected ...

1

At the very least, you need to bias the + input of your opamp to the virtual ground you want to use. Use a resistor divider between your 9v rail and ground to get 4.5V. This will bias the input to the midpoint of your rails. In this configuration, you will need two separate biasing dividers for the two op-amps. A more rational approach might be to ...

0

TLDR version: Start with a 10K pot set to 1K from ground. I just saw the bridge part (which wasn't in the old question). That means the output is taken out of phase from the two amps inside the TDA, so the max level it could reach is 2x the supply rail, i.e. 15V DC (ignoring that it can't swing all the way to rails). If you're going to use an attenuator ...

4

The best scheme for adding ESD protection to inputs to a digital circuit will depend to large degree on the bandwidth of the signal input. The simplest ESD filering is done with an RC low pass filter. A series resistor in the signal line and then a capacitor to GND. This limits how fast of real intended signal can enter the system however and it changes ...

0

As for me HM-10 is almost perfect: cheap supports PIO controlled by AT commands With Apploader iOS app you can even upload Arduino sketched from iOS to Arduino over BLE (for free): http://www.apploader.info

3

Given the vastly changed info... TDA2822 is a low power chip (under a 1W; its datasheet recommends it for "portable cassette players"), and of course the speaker it sends to is only 2.5W (doesn't get that much). Basically you can take the output of this amp (from the speakers' wires) straight to any professional line in audio equipment. It's like plugging in ...

2

You have a few possibilities but here's the simplest. The TDA2030 is a single amplifier chip. The amplifier drives one speaker terminal through a DC-blocking capacitor and the other speaker terminal is connected to ground. If a split power supply (+ com -) is used the DC-blocking capacitor may be omitted. If the device has no earth connection (i.e., the ...

1

Here are the differences I could find: HM-10: power: 3.3v (only) BLE-112: power: 2.0 - 3.6V -- better for coin cell operation, for example HM-10: 28 x 13 x 2.3 mm BLE-112: 18 x 12 x 2.3 mm (smaller) HM-10: available only from China ($6.05, e.g. www.fasttech.com) BLE-112: available from US distributors (Digi-Key & Mouser,$15.66) HM-10: must ...

1

The primary advantage to active low is safety. It is used widely in the C&I world in situations where a lost signal would be devastating. One example would be the water level of a boiler being low, another would be a emergency stop, another would be low fuel pressure. If one of these events happen the machine must be stopped. If the system used active ...

0

Active low signals are more tolerant of noise in some logic families, especially the old TTL. A high TTL signal must be at least 2.8V out and can be as low as 2.0V in. That leaves 0.8V margin for voltage drop and noise. And a pullup resistor to the 5V supply can be added for additional margin. A low TTL signal must be no more than 0.4V out and can be as ...

1

Is there a Microcontroller with 16MB of Ram? I'm pretty sure there are no processors with 16 MB of on-chip RAM. The "16 MB RAM" mentioned in some descriptions of the 68000 allude to the 24-bit external address bus that could, in theory, address a maximum of up to 2^24 bytes = 16 MB of external RAM. My understanding is that the vast majority of systems ...

7

Is there a Microcontroller with 16MB of Ram? Yes. The only one I'm aware of, though, is in the Renesas SuperH family, and doesn't include ROM - so you have to have external flash, but it has 16MBytes of onboard SRAM. I am looking to write a emulator for the Sega Megadrive (Sega Genesis) that runs on AVR. There are no 16MByte SRAM microcontrolers in ...

3

None of the other answers have mentioned that you could just get a chip which runs the m86k instruction set natively: the Coldfire series. A number of instructions have been removed; if they aren't too frequently used they could be emulated by trapping the "invalid instruction" interrupt. However, you'd still need to emulate the Yamaha YM7101 video ...

10

Not going to happen. The largest microcontroller in the ATmega line with support for external memory is the ATmega1284, but this only which has 8 KB of internal SRAM, and can address up to 64 KB of external memory. This isn't going to be sufficient to emulate the Genesis, which had 72 KB of RAM and another 64 KB of video memory. It might be possible to ...

15

Even though the Motorola 68000 and the Sega Genesis are quite old (early 1980's), you are not going to find a low-end (i.e. 8-bit) AVR that can emulate the entire game machine. The Sega Genesis ran at 7.61 MHz and had 72KB of RAM (plus an additional 64KB of video RAM). However the game programs resided in ROM, so you will need additional RAM to hold them ...

0

Look up pnp multivibrator. It is an adjustable square wave circuit. You will need two pnp transistors 3906, 4403 or if you burn those up, you can still use 2907 at a lower amp input, two 100kohm two 2200ohm and two 100ohm transistors, two 1uf capacitors and two diodes and or LEDs. The frequency and voltage are increased by applying more 100kohm resistors ...

2

By setting the output voltage of the circuit to about half the power supply voltage, the output can swing up about equally as much as it can swing down. For many simple input signals (eg. audio), this usually what you want. In practice you want to keep some headroom to prevent distortion. The reason for choosing 5mA is in some sense similar to #1. It means ...

0

Direct answer: no, you do not need a 50V supply. The voltage supply usually is selected according to the highest required voltage of a single component. Lets say you have 1 motor that needs 5V and one LED that needs 2V. You need to select a 5V supply and take care that all other elements that need less will see a lower voltage. This is accomplished by a ...

2

What you are describing is one of the fundamental laws of electronics, called series and parallel circuits. There are many references for such topics, however Ibiblio has been hosting Tony Kuphaldt's excellent series, Lessons In Electric Circuits for nearly a decade. The first volume, 1-DC, will explain how this works and why. The short answer is, you could ...

0

In the very unlikely circumstance that you intend to connect all the motors in series, so they will run simultaneously, you would theoretically need a 50 volt power supply. However, this is unlikely to work well, as the current required by each motor will depend on the load it is required to move. However, you will more likely want the possibility of ...

3

First I would second the old talk to the manufacturer first plan, but then I would say you come up with an idea based on what you know about your radio in/out impedance and your antenna input impedance considering that your goals are likely: to efficiently match your receiver and/or transmitter output to your antenna impedance (smith charts anyone?) DC ...

0

Use 2:4 Decoder and 16 2kx8 ROM in 4x4 manner. ie, for each decoder line enable 4 number of 2kx8 ROM will be enabled.

1

C1 is a DC blocking (coupling) cap exactly as you suspected. R1 is to provide a DC path for the bias current for the input stage of the op-amp. The gain will (1+R2/Rpot) with a negligible error due to finite open loop gain of the amplifier. 1+10000/Rpot = 150, so Rpot = 68.1 ohms. A=146.8 which is within 5% of 150. Note that typical gain-bandwidth for ...

2

I'm not going to give an answer based on your requirement but instead explain a little about the 100MHz commercial FM broadcast band. It generally ranges from 88 to 108 MHz (a 20 MHz span) and the Intermediate Frequency (IF) is chosen to be at 10.7 MHz (slightly higher than twice the range of 20 MHz). With an IF of 10.7 MHz the local oscillator (LO) can be ...

1

The answer depends on what type of transceiver you're designing ! If it is a direct conversion ( also called zero-IF) transceiver then the LO (local oscillator) frequency will be the same as Frf, the frequency you want to receive or transmit. If you're designing a superheterodyne transceiver then LO will not be equal to Frf, the LO will be running at Frf + ...

1

The simplest solution (schematic-wise) is a microcontroller with an ADC and a few lines of code that read the input voltage and control two outputs. Other than that, you could use a quad comparator LM339. Set the thresholds at, say, 0.5V and 1.5V and 2.5V with a simple 4-resistor divider (say 499/1K/1K/2.49K to +5V). Then you have three outputs - either ...

4

A slightly different way to solve your problem is to use AC and handle the two halves differently, as in the circuit below: simulate this circuit – Schematic created using CircuitLab

1

This isn't a table, but it might help you. There is a free RF filter design program at http://iowahills.com/9RFFiltersPage.html You can get the Chebyshev values you want from the program by doing the following. Since the lowest frequency allowed by the program is 1 kHz, set the design frequency to 1/(2*Pi) MHz = 0.159155 MHz. Then enter 1 Ohm for both the ...

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