Two-Input DL AND Gate www.play-hookey.com Wed,||||||||||||||||||||||||||||| Two-Input DL AND Gate Introduction The Diode Logic (DL) AND gate is just as simple as the DL OR gate, although it is configured a bit differently. Schematic Diagram As shown to the right, a Diode Logic AND gate consists of nothing more than diodes (one for each input signal) and a resistor. As with the DL OR gate, the 10K resistor provides a reference connection. Unlike the OR gate, however, this is a reference to +5 volts, rather than to ground. If there are no input signals connected to the diodes, the output will be +5 volts, or logic 1. Thus, an open input will not affect the rest of the circuit, which will continue to operate normally. It is possible to add any number of input diodes to this circuit, each with its separate input signal. However, two inputs are quite sufficient to demonstrate the operation of the circuit. Parts List To construct and test the two-input DL AND gate on your breadboard socket, you will need the following components. ゲート 自衛隊 彼の地にて、斯く戦えり 第01-10巻 漫画 無料ダウンロード Comics Free Dl Online Zip Rar From Rapidgator Uploaded DataFile. Priefert’s D-Gates get their name from the unique “D-shaped” tubing from which they are constructed. This shape of tubing offers maximum rigidity and strength in a lightweight gate. Track Delta (DL) #400 flight from Frankfurt Int'l to John F Kennedy Intl. Most of them can be the components left over from your experiment with the DL OR gate: • (1) 10K ohm resistor (brown-black-orange). • (2) 1N914 diodes or equivalent. • (1) 10' length of white hookup wire (you may substitute other colors if necessary). • (2) 3' lengths of orange hookup wire (again, substitutions are acceptable). Constructing the Circuit Your DL AND gate will be constructed in the same place as your DL OR gate from the previous experiment. You can use the same diodes and jumpers, but we strongly urge you to prepare a new 10K resistor, since the lead spacing is different for this experiment. Circuit Assembly. Performing the Experiment To perform this experiment, turn on power to your experimental circuit, and then observe the L0 as you set S0 and S1 to all four possible combinations of two switches. For each input combination, note the logical output state of the circuit as indicated by the L0 and record that result in the form to the right. Does your result match the normal behavior of an OR gate? Also measure the output voltage for each combination and record that voltage in the text field for that combination of inputs. Are the measured voltages legal logic signals? Are they what you expected? When you have completed your determinations, turn off the power to your experimental circuit. Inputs Output S2 S1 L0 Voltage 0 0 0 1 1 0 1 1 Discussion You should have found that the L0 remains off when either switch sends a logic 0 to the gate, and turns on only when both S0 and S1 send a logic 1 to the gate. This is normal AND gate behavior. However, your measured voltages may have seemed a bit strange. A logic 0 output measured about 0.6-0.7 volt, which is the normal diode voltage drop you would expect. However, the logic 1 output voltage was only about 4.5 volts. In view of the fact that all resistors pull the output up to +5 volts as shown in the schematic diagram, this seems odd. What's causing this discrepancy? The answer is the LED driver circuit for L0. Remember that the gate output is connected to L0, so that circuit constitutes a load on this gate. It consists of a 100K resistor (plus a CMOS gate input) connected to ground. The resistor forms a voltage divider with the 10K resistor in the AND gate. This will pull the output voltage down somewhat, causing the result you obtained. Note that if we used the RTL-based LED driver circuit here, the load would be a 22K resistor plus a forward-biased diode. This would have a far greater effect on the output voltage of this gate. Although the error caused by the input circuit to L0 is small enough to allow the circuit to still operate within legal voltages for both logic levels, it does point up a potential problem: we must allow for possible interactions between logic gates, and make sure that the signal does not get degraded too far. Make sure power is turned off, but leave your experimental circuit in place. The next experiment will expand on this circuit to continue our work with Diode Logic. Prev: Next: All pages on www.play-hookey.com copyright © 1996, 2000-2015 by Please address queries and suggestions to.
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