| There are two types of devices in which it may be | | | | The oscillation would have initial amplitude proportional |
| necessary to generate amplitude modulation. The first | | | | to the size of the current pulse and a decay rate |
| of these is, the amplitude modulation transmitter | | | | dependent on the time constant of the circuit. Since a |
| generates such high power that its prime requirement | | | | train of pulses is fed to the tank circuit here, each pulse |
| is efficiency, so quite complex means of amplitude | | | | will cause a complete sine wave proportional in |
| modulation generation may be used. The other device | | | | amplitude to the size of this pulse. This will be followed |
| is the amplitude modulation generator. Here the | | | | by the next sine wave proportional to the size of the |
| amplitude modulation is produced at such a low power | | | | next applied pulse and so on. Bearing in mind that at |
| level that the simplicity is a more important requirement | | | | least ten times as many pulses per audio cycle are |
| than efficiency. Although the methods of generating | | | | fed to a practical circuit we see that an extremely |
| amplitude modulation can be different but generating | | | | good approximation of an amplitude modulated wave |
| high power are always taken care of. | | | | will result if the original current pulses are made |
| In order to generate amplitude modulation wave it is | | | | proportional to the modulating voltage. The process is |
| necessary merely to apply the series of current pulses | | | | known as the flywheel effect of the tuned circuit, and |
| to a tuned circuit. Each pulse, if it were the only one, | | | | it works best with a tuned circuit whose operating |
| would initiate a damped oscillation in the tuned circuit. | | | | point is not too low. |