80C39 and MCS48 based Process Controller
The Early Microcontroller : 80C39 is a CMOS Version of 8048 the one that preceded 8031-8051. MCS48 is the set for that, MCS51 is the […]
Embedded-Systems
Battery Backup for SRAM or Microcontroller
This circuit can be used as a low cost SRAM and Microcontroller or Microprocessor Battery Backup. All the diodes are 1N4148, The diodes prevent battery […]
Digital to Analog Converter with uC Watchdog
This is the continuation of the earlier post. Part of 80C39 based Process Controller. In this schematic you can see the Watchdog and D/A Converter. […]
Battery Backup Supply
This is a 9V power supply which will work even on power failure. It uses a rechargeable battery and regulators. A transformer with 15-0-15 AC […]
Digital gain control of Opamp.
The gain of U1 can be controlled by a digital binary 1248 nibble at ABC. The gain at digital 000 is unity or 1 and […]
555 based Reset Generator
You must have read all the circuits and explanation on the other pages at delabs to understand this, as i cannot repeat the same thing […]
Crystal Oscillator – Parallel Resonant
74HCU04 is a chip that was made for this purpose, HCT may not work for such a circuit. C1 and C2 can go to upto […]
Precision Attenuator for Digital uC Control
When Instruments are designed a analog front end is essential and also as most equipment have digital or microcontroller interface the analog circuit needs to […]